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Peterson MA, Campbell ES. Backward masking implicates cortico-cortical recurrent processes in convex figure context effects and cortico-thalamic recurrent processes in resolving figure-ground ambiguity. Front Psychol 2023; 14:1243405. [PMID: 37809293 PMCID: PMC10552270 DOI: 10.3389/fpsyg.2023.1243405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 08/17/2023] [Indexed: 10/10/2023] Open
Abstract
Introduction Previous experiments purportedly showed that image-based factors like convexity were sufficient for figure assignment. Recently, however, we found that the probability of perceiving a figure on the convex side of a central border was only slightly higher than chance for two-region displays and increased with the number of display regions; this increase was observed only when the concave regions were homogeneously colored. These convex figure context effects (CEs) revealed that figure assignment in these classic displays entails more than a response to local convexity. A Bayesian observer replicated the convex figure CEs using both a convexity object prior and a new, homogeneous background prior and made the novel prediction that the classic displays in which both the convex and concave regions were homogeneous were ambiguous during perceptual organization. Methods Here, we report three experiments investigating the proposed ambiguity and examining how the convex figure CEs unfold over time with an emphasis on whether they entail recurrent processing. Displays were shown for 100 ms followed by pattern masks after ISIs of 0, 50, or 100 ms. The masking conditions were designed to add noise to recurrent processing and therefore to delay the outcome of processes in which they play a role. In Exp. 1, participants viewed two- and eight-region displays with homogeneous convex regions (homo-convex displays; the putatively ambiguous displays). In Exp. 2, participants viewed putatively unambiguous hetero-convex displays. In Exp. 3, displays and masks were presented to different eyes, thereby delaying mask interference in the thalamus for up to 100 ms. Results and discussion The results of Exps. 1 and 2 are consistent with the interpretation that recurrent processing is involved in generating the convex figure CEs and resolving the ambiguity of homo-convex displays. The results of Exp. 3 suggested that corticofugal recurrent processing is involved in resolving the ambiguity of homo-convex displays and that cortico-cortical recurrent processes play a role in generating convex figure CEs and these two types of recurrent processes operate in parallel. Our results add to evidence that perceptual organization evolves dynamically and reveal that stimuli that seem unambiguous can be ambiguous during perceptual organization.
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Affiliation(s)
- Mary A. Peterson
- Department of Psychology, University of Arizona, Tucson, AZ, United States
- Cognitive Science Program, University of Arizona, Tucson, AZ, United States
| | - Elizabeth Salvagio Campbell
- Department of Psychology, University of Arizona, Tucson, AZ, United States
- Cognitive Science Program, University of Arizona, Tucson, AZ, United States
- College of Medicine Tucson, University of Arizona, Tucson, AZ, United States
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Danieli K, Guyon A, Bethus I. Episodic Memory formation: A review of complex Hippocampus input pathways. Prog Neuropsychopharmacol Biol Psychiatry 2023; 126:110757. [PMID: 37086812 DOI: 10.1016/j.pnpbp.2023.110757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/08/2023] [Accepted: 03/22/2023] [Indexed: 04/24/2023]
Abstract
Memories of everyday experiences involve the encoding of a rich and dynamic representation of present objects and their contextual features. Traditionally, the resulting mnemonic trace is referred to as Episodic Memory, i.e. the "what", "where" and "when" of a lived episode. The journey for such memory trace encoding begins with the perceptual data of an experienced episode handled in sensory brain regions. The information is then streamed to cortical areas located in the ventral Medio Temporal Lobe, which produces multi-modal representations concerning either the objects (in the Perirhinal cortex) or the spatial and contextual features (in the parahippocampal region) of the episode. Then, this high-level data is gated through the Entorhinal Cortex and forwarded to the Hippocampal Formation, where all the pieces get bound together. Eventually, the resulting encoded neural pattern is relayed back to the Neocortex for a stable consolidation. This review will detail these different stages and provide a systematic overview of the major cortical streams toward the Hippocampus relevant for Episodic Memory encoding.
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Affiliation(s)
| | - Alice Guyon
- Université Cote d'Azur, Neuromod Institute, France; Université Cote d'Azur, CNRS UMR 7275, IPMC, Valbonne, France
| | - Ingrid Bethus
- Université Cote d'Azur, Neuromod Institute, France; Université Cote d'Azur, CNRS UMR 7275, IPMC, Valbonne, France
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Skocypec RM, Peterson MA. Semantic Expectation Effects on Object Detection: Using Figure Assignment to Elucidate Mechanisms. Vision (Basel) 2022; 6:vision6010019. [PMID: 35324604 PMCID: PMC8953613 DOI: 10.3390/vision6010019] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 03/02/2022] [Accepted: 03/15/2022] [Indexed: 11/16/2022] Open
Abstract
Recent evidence suggesting that object detection is improved following valid rather than invalid labels implies that semantics influence object detection. It is not clear, however, whether the results index object detection or feature detection. Further, because control conditions were absent and labels and objects were repeated multiple times, the mechanisms are unknown. We assessed object detection via figure assignment, whereby objects are segmented from backgrounds. Masked bipartite displays depicting a portion of a mono-oriented object (a familiar configuration) on one side of a central border were shown once only for 90 or 100 ms. Familiar configuration is a figural prior. Accurate detection was indexed by reports of an object on the familiar configuration side of the border. Compared to control experiments without labels, valid labels improved accuracy and reduced response times (RTs) more for upright than inverted objects (Studies 1 and 2). Invalid labels denoting different superordinate-level objects (DSC; Study 1) or same superordinate-level objects (SSC; Study 2) reduced accuracy for upright displays only. Orientation dependency indicates that effects are mediated by activated object representations rather than features which are invariant over orientation. Following invalid SSC labels (Study 2), accurate detection RTs were longer than control for both orientations, implicating conflict between semantic representations that had to be resolved before object detection. These results demonstrate that object detection is not just affected by semantics, it entails semantics.
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Affiliation(s)
- Rachel M. Skocypec
- Visual Perception Lab, Department of Psychology, School of Mind, Brain and Behavior, University of Arizona, Tucson, AZ 85721, USA
- Cognitive Science Program, School of Mind, Brain and Behavior, University of Arizona, Tucson, AZ 85721, USA
- Correspondence: (R.M.S.); (M.A.P.)
| | - Mary A. Peterson
- Visual Perception Lab, Department of Psychology, School of Mind, Brain and Behavior, University of Arizona, Tucson, AZ 85721, USA
- Cognitive Science Program, School of Mind, Brain and Behavior, University of Arizona, Tucson, AZ 85721, USA
- Correspondence: (R.M.S.); (M.A.P.)
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Verbal and Nonverbal Memory in Neurodegenerative and Stroke Aphasia: Evidence From the Turkish Version of the Three Words Three Shapes Test. Cogn Behav Neurol 2022; 35:49-65. [PMID: 35239599 DOI: 10.1097/wnn.0000000000000294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 08/05/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND Although language impairment is the most salient feature of cognitive impairment in both primary progressive aphasia (PPA) and stroke aphasia (SA), memory can also be impaired in both patient populations. OBJECTIVE To identify distinctive features of verbal and nonverbal memory processing in individuals with PPA and those with SA. METHOD We gave individuals with PPA (n = 14), those with SA (n = 8), and healthy controls (HC; n = 13) a comprehensive neuropsychological test battery and the Turkish version of the Three Words Three Shapes Test (3W3S-Turkish). The 3W3S-Turkish Test includes five subtests: Copy, Incidental Recall, Acquisition, Delayed Recall, and Recognition. High-resolution brain scans were performed in a subset of individuals with PPA and those with SA. Lesion distribution was limited to the dorsal language areas in the SA group, whereas peak atrophy areas in the PPA group extended beyond the language network, including the medial temporal lobe, precuneus, and posterior/medial portions of the cingulate cortex. RESULTS Both the PPA and SA groups showed impairment in incidental recall, and the PPA group showed additional impairment in delayed recall. Greater impairment for verbal stimuli suggestive of material-specific memory impairment was evident in the PPA group's scores on the Incidental Recall and Delayed Recall subtests. Both aphasia groups retained the acquired information regardless of material type. CONCLUSION Although both aphasia groups shared similarities in the involvement of the dorsal prefrontal working memory/attention network, the PPA group showed greater impairment in delayed recall compared with the SA group.
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Task set and instructions influence the weight of figural priors: A psychophysical study with extremal edges and familiar configuration. Atten Percept Psychophys 2021; 83:2709-2727. [PMID: 33880711 PMCID: PMC8302519 DOI: 10.3758/s13414-021-02282-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2021] [Indexed: 11/08/2022]
Abstract
In figure-ground organization, the figure is defined as a region that is both "shaped" and "nearer." Here we test whether changes in task set and instructions can alter the outcome of the cross-border competition between figural priors that underlies figure assignment. Extremal edge (EE), a relative distance prior, has been established as a strong figural prior when the task is to report "which side is nearer?" In three experiments using bipartite stimuli, EEs competed and cooperated with familiar configuration, a shape prior for figure assignment in a "which side is shaped?" task." Experiment 1 showed small but significant effects of familiar configuration for displays sketching upright familiar objects, although "shaped-side" responses were predominantly determined by EEs. In Experiment 2, instructions regarding the possibility of perceiving familiar shapes were added. Now, although EE remained the dominant prior, the figure was perceived on the familiar-configuration side of the border on a significantly larger percentage of trials across all display types. In Experiment 3, both task set (nearer/shaped) and the presence versus absence of instructions emphasizing that familiar objects might be present were manipulated within subjects. With familiarity thus "primed," effects of task set emerged when EE and familiar configuration favored opposite sides as figure. Thus, changing instructions can modulate the weighing of figural priors for shape versus distance in figure assignment in a manner that interacts with task set. Moreover, we show that the influence of familiar parts emerges in participants without medial temporal lobe/ perirhinal cortex brain damage when instructions emphasize that familiar objects might be present.
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Sasia B, Cacciamani L. High-definition transcranial direct current stimulation of the lateral occipital cortex influences figure-ground perception. Neuropsychologia 2021; 155:107792. [PMID: 33610616 DOI: 10.1016/j.neuropsychologia.2021.107792] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 01/11/2021] [Accepted: 02/14/2021] [Indexed: 01/28/2023]
Abstract
Prior work has shown that the lateral occipital cortex (LO) is involved in recognition of objects and their parts, as well as segregation of that object (or "figure") from its background. No studies, though, have examined how LO's functioning is influenced by non-invasive brain stimulation, particularly during a figure-ground perception task. The present study tested whether high-definition transcranial direct current stimulation (HD-tDCS) to right LO influences the effects of familiarity on figure-ground perception. Following 20 min of offline anodal stimulation (or sham), participants viewed masked stimuli consisting of two regions separated by a vertical border and were asked to report which region they perceived as figure. One region was the "critical" region, which either depicted a portion of a familiar object ("Familiar" stimuli), or a familiar object with its parts rearranged into a novel configuration ("Part-rearranged" stimuli). Previous research using these stimuli has found higher reports of the critical region as figure for Familiar vs. Part-rearranged displays, demonstrating the effect of familiarity on figure assignment. The results of the current study showed that HD-tDCS to right LO significantly influenced this typical behavioral pattern. Specifically, stimulation (vs. sham) increased reports of the critical region as figure for Part-rearranged stimuli, bringing perception of these displays up to the level of the Familiar stimuli. We interpret this finding as evidence that stimulation of right LO increased participants' reliance on the familiarity of the parts in their figure-ground judgements-a finding consistent with and extending previous research showing that LO is indeed sensitive to object parts. This is the first study showing that HD-tDCS to LO can influence the effects of familiarity on figure-ground perception.
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Affiliation(s)
- Brooke Sasia
- California Polytechnic State University, San Luis Obispo, CA, USA.
| | - Laura Cacciamani
- California Polytechnic State University, San Luis Obispo, CA, USA
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Griffiths TD, Lad M, Kumar S, Holmes E, McMurray B, Maguire EA, Billig AJ, Sedley W. How Can Hearing Loss Cause Dementia? Neuron 2020; 108:401-412. [PMID: 32871106 PMCID: PMC7664986 DOI: 10.1016/j.neuron.2020.08.003] [Citation(s) in RCA: 159] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 07/31/2020] [Accepted: 08/05/2020] [Indexed: 12/11/2022]
Abstract
Epidemiological studies identify midlife hearing loss as an independent risk factor for dementia, estimated to account for 9% of cases. We evaluate candidate brain bases for this relationship. These bases include a common pathology affecting the ascending auditory pathway and multimodal cortex, depletion of cognitive reserve due to an impoverished listening environment, and the occupation of cognitive resources when listening in difficult conditions. We also put forward an alternate mechanism, drawing on new insights into the role of the medial temporal lobe in auditory cognition. In particular, we consider how aberrant activity in the service of auditory pattern analysis, working memory, and object processing may interact with dementia pathology in people with hearing loss. We highlight how the effect of hearing interventions on dementia depends on the specific mechanism and suggest avenues for work at the molecular, neuronal, and systems levels to pin this down.
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Affiliation(s)
- Timothy D Griffiths
- Biosciences Institute, Newcastle University Medical School, Newcastle upon Tyne NE2 4HH, UK; Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London WC1N 3AR, UK; Human Brain Research Laboratory, Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, IA 52242, USA.
| | - Meher Lad
- Biosciences Institute, Newcastle University Medical School, Newcastle upon Tyne NE2 4HH, UK
| | - Sukhbinder Kumar
- Biosciences Institute, Newcastle University Medical School, Newcastle upon Tyne NE2 4HH, UK
| | - Emma Holmes
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London WC1N 3AR, UK
| | - Bob McMurray
- Departments of Psychological and Brain Sciences, Communication Sciences and Disorders, Otolaryngology, University of Iowa, Iowa City, IA 52242, USA
| | - Eleanor A Maguire
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London WC1N 3AR, UK
| | | | - William Sedley
- Biosciences Institute, Newcastle University Medical School, Newcastle upon Tyne NE2 4HH, UK
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Kozunov VV, West TO, Nikolaeva AY, Stroganova TA, Friston KJ. Object recognition is enabled by an experience-dependent appraisal of visual features in the brain's value system. Neuroimage 2020; 221:117143. [PMID: 32650054 PMCID: PMC7762843 DOI: 10.1016/j.neuroimage.2020.117143] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 06/13/2020] [Accepted: 07/02/2020] [Indexed: 01/05/2023] Open
Abstract
This paper addresses perceptual synthesis by comparing responses evoked by visual stimuli before and after they are recognized, depending on prior exposure. Using magnetoencephalography, we analyzed distributed patterns of neuronal activity - evoked by Mooney figures - before and after they were recognized as meaningful objects. Recognition induced changes were first seen at 100-120 ms, for both faces and tools. These early effects - in right inferior and middle occipital regions - were characterized by an increase in power in the absence of any changes in spatial patterns of activity. Within a later 210-230 ms window, a quite different type of recognition effect appeared. Regions of the brain's value system (insula, entorhinal cortex and cingulate of the right hemisphere for faces and right orbitofrontal cortex for tools) evinced a reorganization of their neuronal activity without an overall power increase in the region. Finally, we found that during the perception of disambiguated face stimuli, a face-specific response in the right fusiform gyrus emerged at 240-290 ms, with a much greater latency than the well-known N170m component, and, crucially, followed the recognition effect in the value system regions. These results can clarify one of the most intriguing issues of perceptual synthesis, namely, how a limited set of high-level predictions, which is required to reduce the uncertainty when resolving the ill-posed inverse problem of perception, can be available before category-specific processing in visual cortex. We suggest that a subset of local spatial features serves as partial cues for a fast re-activation of object-specific appraisal by the value system. The ensuing top-down feedback from value system to visual cortex, in particular, the fusiform gyrus enables high levels of processing to form category-specific predictions. This descending influence of the value system was more prominent for faces than for tools, the fact that reflects different dependence of these categories on value-related information.
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Affiliation(s)
- Vladimir V Kozunov
- MEG Centre, Moscow State University of Psychology and Education, Moscow, 29 Sretenka, Russia.
| | - Timothy O West
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK; Wellcome Trust Centre for Neuroimaging, 12 Queen Square, University College London, London, WC1N 3AR, UK.
| | - Anastasia Y Nikolaeva
- MEG Centre, Moscow State University of Psychology and Education, Moscow, 29 Sretenka, Russia.
| | - Tatiana A Stroganova
- MEG Centre, Moscow State University of Psychology and Education, Moscow, 29 Sretenka, Russia.
| | - Karl J Friston
- Wellcome Trust Centre for Neuroimaging, 12 Queen Square, University College London, London, WC1N 3AR, UK.
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Flowers CS, Orsten-Hooge KD, Jannuzi BGL, Peterson MA. Normative data for an expanded set of stimuli for testing high-level influences on object perception: OMEFA-II. PLoS One 2020; 15:e0224471. [PMID: 32797090 PMCID: PMC7428090 DOI: 10.1371/journal.pone.0224471] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 07/28/2020] [Indexed: 11/18/2022] Open
Abstract
We present normative data for an expanded set of stimuli designed to investigate past experience effects on object detection. The stimuli are vertically-elongated “bipartite” displays comprising two equal-area regions meeting at an articulated central border. When the central border is assigned to one side, a shaped figure (i.e., an object) is detected on that side. Participants viewing brief masked exposures typically detect figures more often on the critical side of Intact displays where a common (“familiar”) object is depicted than on a matched critical side of Part-Rearranged (PR) displays comprising the same parts arranged in novel configurations. This pattern of results showed that past experience in the form of familiar configuration rather than familiar parts is a prior for figure assignment. Spurred by research implicating a network involving the perirhinal cortex of the medial temporal lobe in these familiar configuration effects, we enlarged the stimulus set from 24 to 48 base stimuli to increase its usefulness for behavioral, neuropsychological, and neuroimaging experiments. We measured the percentage of participants who agreed on a single interpretation for each side of Intact, Upright PR, and Inverted PR displays (144 displays; 288 sides) under long exposure conditions. High inter-subject agreement is taken to operationally define a familiar configuration. This new stimulus set is well-suited to investigate questions concerning how parts and wholes are integrated and how high- and low-level brain areas interact in object detection. This set also allows tests of predictions regarding cross-border competition in figure assignment and assessments of individual differences. The displays, their image statistics, and normative data are available online (https://osf.io/j9kz2/).
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Affiliation(s)
- Colin S. Flowers
- Department of Psychology, University of Arizona, Tucson, Arizona, United States of America
- * E-mail:
| | - Kimberley D. Orsten-Hooge
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, Texas, United States of America
| | - Barnes G. L. Jannuzi
- Neuroscience and Cognitive Science Program, University of Arizona, Tucson, Arizona, United States of America
| | - Mary A. Peterson
- Department of Psychology, University of Arizona, Tucson, Arizona, United States of America
- Cognitive Science Program, University of Arizona, Tucson, Arizona, United States of America
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10
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Prior Experience Alters the Appearance of Blurry Object Borders. Sci Rep 2020; 10:5821. [PMID: 32242057 PMCID: PMC7118174 DOI: 10.1038/s41598-020-62728-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 03/17/2020] [Indexed: 01/02/2023] Open
Abstract
Object memories activated by borders serve as priors for figure assignment: figures are more likely to be perceived on the side of a border where a well-known object is sketched. Do object memories also affect the appearance of object borders? Memories represent past experience with objects; memories of well-known objects include many with sharp borders because they are often fixated. We investigated whether object memories affect appearance by testing whether blurry borders appear sharper when they are contours of well-known objects versus matched novel objects. Participants viewed blurry versions of one familiar and one novel stimulus simultaneously for 180 ms; then made comparative (Exp. 1) or equality judgments regarding perceived blur (Exps. 2–4). For equivalent levels of blur, the borders of well-known objects appeared sharper than those of novel objects. These results extend evidence for the influence of past experience to object appearance, consistent with dynamic interactive models of perception.
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Liang JC, Erez J, Zhang F, Cusack R, Barense MD. Experience Transforms Conjunctive Object Representations: Neural Evidence for Unitization After Visual Expertise. Cereb Cortex 2020; 30:2721-2739. [DOI: 10.1093/cercor/bhz250] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Abstract
Certain transformations must occur within the brain to allow rapid processing of familiar experiences. Complex objects are thought to become unitized, whereby multifeature conjunctions are retrieved as rapidly as a single feature. Behavioral studies strongly support unitization theory, but a compelling neural mechanism is lacking. Here, we examined how unitization transforms conjunctive representations to become more “feature-like” by recruiting posterior regions of the ventral visual stream (VVS) whose architecture is specialized for processing single features. We used functional magnetic resonance imaging to scan humans before and after visual training with novel objects. We implemented a novel multivoxel pattern analysis to measure a conjunctive code, which represented a conjunction of object features above and beyond the sum of the parts. Importantly, a multivoxel searchlight showed that the strength of conjunctive coding in posterior VVS increased posttraining. Furthermore, multidimensional scaling revealed representational separation at the level of individual features in parallel to the changes at the level of feature conjunctions. Finally, functional connectivity between anterior and posterior VVS was higher for novel objects than for trained objects, consistent with early involvement of anterior VVS in unitizing feature conjunctions in response to novelty. These data demonstrate that the brain implements unitization as a mechanism to refine complex object representations over the course of multiple learning experiences.
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Affiliation(s)
- Jackson C Liang
- Department of Psychology, University of Toronto, Toronto, ON M5S 3G3, Canada
| | - Jonathan Erez
- Department of Psychology, Brain and Mind Institute, Western Interdisciplinary Research Building, Western University, London, ON N6A 5B7, Canada
| | - Felicia Zhang
- Department of Psychology, Princeton University, Princeton, NJ 08540, USA
| | - Rhodri Cusack
- School of Psychology, Trinity College Dublin, Dublin, Ireland amd
| | - Morgan D Barense
- Department of Psychology, University of Toronto, Toronto, ON M5S 3G3, Canada
- Rotman Research Institute, Toronto, ON M6A 2E1, Canada
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12
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Loganovsky KN, Fedirko PA, Kuts KV, Marazziti D, Antypchuk KY, Perchuk IV, Babenko TF, Loganovska TK, Kolosynska OO, Kreinis GY, Gresko MV, Masiuk SV, Zdorenko LL, Zdanevich NA, Garkava NA, Dorichevska RY, Vasilenko ZL, Kravchenko VI, Drosdova NV, Yefimova YV. BRAIN AND EYE AS POTENTIAL TARGETS FOR IONIZING RADIATION IMPACT. Part І. THE CONSEQUENCES OF IRRADIATION OF THE PARTICIPANTS OF THE LIQUIDATION OF THE CHORNOBYL ACCIDENT. PROBLEMY RADIAT︠S︡IĬNOÏ MEDYT︠S︡YNY TA RADIOBIOLOHIÏ 2020; 25:90-129. [PMID: 33361831 DOI: 10.33145/2304-8336-2020-25-90-129] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND Exposure to ionizing radiation could affect the brain and eyes leading to cognitive and vision impairment, behavior disorders and performance decrement during professional irradiation at medical radiology, includinginterventional radiological procedures, long-term space flights, and radiation accidents. OBJECTIVE The objective was to analyze the current experimental, epidemiological, and clinical data on the radiation cerebro-ophthalmic effects. MATERIALS AND METHODS In our analytical review peer-reviewed publications via the bibliographic and scientometric bases PubMed / MEDLINE, Scopus, Web of Science, and selected papers from the library catalog of NRCRM - theleading institution in the field of studying the medical effects of ionizing radiation - were used. RESULTS The probable radiation-induced cerebro-ophthalmic effects in human adults comprise radiation cataracts,radiation glaucoma, radiation-induced optic neuropathy, retinopathies, angiopathies as well as specific neurocognitive deficit in the various neuropsychiatric pathology including cerebrovascular pathology and neurodegenerativediseases. Specific attention is paid to the likely stochastic nature of many of those effects. Those prenatally and inchildhood exposed are a particular target group with a higher risk for possible radiation effects and neurodegenerative diseases. CONCLUSIONS The experimental, clinical, epidemiological, anatomical and pathophysiological rationale for visualsystem and central nervous system (CNS) radiosensitivity is given. The necessity for further international studieswith adequate dosimetric support and the follow-up medical and biophysical monitoring of high radiation riskcohorts is justified. The first part of the study currently being published presents the results of the study of theeffects of irradiation in the participants of emergency works at the Chornobyl Nuclear Power Plant (ChNPP).
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Affiliation(s)
- K N Loganovsky
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - P A Fedirko
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - K V Kuts
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - D Marazziti
- Dipartimento di Medicina Clinica e Sperimentale Section of Psychiatry, University of Pisa, Via Roma, 67, I 56100, Pisa, Italy
| | - K Yu Antypchuk
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - I V Perchuk
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - T F Babenko
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - T K Loganovska
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - O O Kolosynska
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - G Yu Kreinis
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - M V Gresko
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - S V Masiuk
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - L L Zdorenko
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - N A Zdanevich
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - N A Garkava
- State Institution «Dnipropetrovsk Medical Academy of the Ministry of Health of Ukraine», 9 Vernadsky Street, Dnipro, 49044, Ukraine
| | - R Yu Dorichevska
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - Z L Vasilenko
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - V I Kravchenko
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - N V Drosdova
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - Yu V Yefimova
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
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13
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Ross DA, Sadil P, Wilson DM, Cowell RA. Hippocampal Engagement during Recall Depends on Memory Content. Cereb Cortex 2019; 28:2685-2698. [PMID: 28666344 DOI: 10.1093/cercor/bhx147] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Indexed: 01/22/2023] Open
Abstract
The hippocampus is considered pivotal to recall, allowing retrieval of information not available in the immediate environment. In contrast, neocortex is thought to signal familiarity, contributing to recall only when called upon by the hippocampus. However, this view is not compatible with representational accounts of memory, which reject the mapping of cognitive processes onto brain regions. According to representational accounts, the hippocampus is not engaged by recall per se, rather it is engaged whenever hippocampal representations are required. To test whether hippocampus is engaged by recall when hippocampal representations are not required, we used functional imaging and a non-associative recall task, with images (objects, scenes) studied in isolation, and image patches as cues. As predicted by a representational account, hippocampal activation was modulated by the content of the recalled memory, increasing during recall of scenes-which are known to be processed by hippocampus-but not during recall of objects. Object recall instead engaged neocortical regions known to be involved in object-processing. Further supporting the representational account, effective connectivity analyses revealed that changes in functional activation during recall were driven by increased information flow from neocortical sites, rather than by the spreading of recall-related activation from hippocampus back to neocortex.
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Affiliation(s)
- David A Ross
- Department of Psychology, University of Massachusetts, Amherst, MA, USA
| | - Patrick Sadil
- Department of Psychology, University of Massachusetts, Amherst, MA, USA
| | - D Merika Wilson
- Department of Psychology, University of Massachusetts, Amherst, MA, USA
| | - Rosemary A Cowell
- Department of Psychology, University of Massachusetts, Amherst, MA, USA
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14
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Gaynor LS, Curiel RE, Penate A, Rosselli M, Burke SN, Wicklund M, Loewenstein DA, Bauer RM. Visual Object Discrimination Impairment as an Early Predictor of Mild Cognitive Impairment and Alzheimer's Disease. J Int Neuropsychol Soc 2019; 25:688-698. [PMID: 31111810 PMCID: PMC6688903 DOI: 10.1017/s1355617719000316] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Detection of cognitive impairment suggestive of risk for Alzheimer's disease (AD) progression is crucial to the prevention of incipient dementia. This study was performed to determine if performance on a novel object discrimination task improved identification of earlier deficits in older adults at risk for AD. METHOD In total, 135 participants from the 1Florida Alzheimer's Disease Research Center [cognitively normal (CN), Pre-mild cognitive impairment (PreMCI), amnestic mild cognitive impairment (aMCI), and dementia] completed a test of object discrimination and traditional memory measures in the context of a larger neuropsychological and clinical evaluation. RESULTS The Object Recognition and Discrimination Task (ORDT) revealed significant differences between the PreMCI, aMCI, and dementia groups versus CN individuals. Moreover, relative risk of being classified as PreMCI rather than CN increased as an inverse function of ORDT score. DISCUSSION Overall, the obtained results suggest that a novel object discrimination task improves the detection of very early AD-related cognitive impairment, increasing the window for therapeutic intervention. (JINS, 2019, 25, 688-698).
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Affiliation(s)
- Leslie S. Gaynor
- Clinical and Health Psychology Department, University of
Florida, Gainesville, Florida
| | - Rosie E. Curiel
- Department of Psychiatry and Center for Cognitive
Neuroscience and Aging, University of Miami Miller School of Medicine, Miami,
Florida
- 1Florida Alzheimer’s Disease Research Center
| | - Ailyn Penate
- Wien Center for Alzheimer’s Disease and Memory
Disorders, Miami Beach, Florida
| | - Mónica Rosselli
- Department of Psychology, Florida Atlantic University, Boca
Raton, Florida
- 1Florida Alzheimer’s Disease Research Center
| | - Sara N. Burke
- McKnight Brain Institute and Department of Neuroscience,
University of Florida, Gainesville, Florida
- 1Florida Alzheimer’s Disease Research Center
| | - Meredith Wicklund
- Department of Neurology, University of Florida College of
Medicine, University of Florida
- 1Florida Alzheimer’s Disease Research Center
| | - David A. Loewenstein
- Department of Psychiatry and Center for Cognitive
Neuroscience and Aging, University of Miami Miller School of Medicine, Miami,
Florida
- 1Florida Alzheimer’s Disease Research Center
| | - Russell M. Bauer
- Clinical and Health Psychology Department, University of
Florida, Gainesville, Florida
- 1Florida Alzheimer’s Disease Research Center
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15
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Folstein JR, Monfared SS. Extended categorization of conjunction object stimuli decreases the latency of attentional feature selection and recruits orthography-linked ERPs. Cortex 2019; 120:49-65. [PMID: 31233910 DOI: 10.1016/j.cortex.2019.05.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Revised: 04/29/2019] [Accepted: 05/20/2019] [Indexed: 11/28/2022]
Abstract
The role of attention in driving perceptual expertise effects is controversial. The current study addressed the effect of training on ERP components related to and independent of attentional feature selection. Participants learned to categorize cartoon animals over six training sessions (8,800 trials) after which ERPs were recorded during a target detection task performed on trained and untrained stimulus sets. The onset of the selection negativity, an ERP component indexing attentional modulation, was about 60 msec earlier for trained than untrained stimuli. Trained stimuli also elicited centro-parietal N200 and N320 components that were insensitive to attentional feature selection. The scalp distribution and timecourse of these components were better matched by studies of orthography than object expertise. Source localization using eLORETA suggested that the strongest neural sources of the selection negativity were in right ventral temporal cortex whereas the strongest sources of the N200/N320 components were in left ventral temporal cortex, again consistent with the hypothesis that training recruited orthography related areas. Overall, training altered neural processes related to attentional selection, but also affected neural processes that were independent of feature selection.
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16
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Peterson MA. Past experience and meaning affect object detection: A hierarchical Bayesian approach. PSYCHOLOGY OF LEARNING AND MOTIVATION 2019. [DOI: 10.1016/bs.plm.2019.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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17
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Recognition memory shielded from semantic but not perceptual interference in normal aging. Neuropsychologia 2018; 119:448-463. [PMID: 30071206 DOI: 10.1016/j.neuropsychologia.2018.07.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 07/02/2018] [Accepted: 07/28/2018] [Indexed: 12/15/2022]
Abstract
Normal aging impairs long-term declarative memory, and evidence suggests that this impairment may be driven partly by structural or functional changes in the medial temporal lobe (MTL). Theories of MTL memory function therefore make predictions for age-related memory loss. One theory - the Representational-Hierarchical account - makes two specific predictions. First, recognition memory performance in older participants should be impaired by feature-level interference, in which studied items contain many shared, and thus repeatedly appearing, perceptual features. Second, if the interference in a recognition memory task - i.e., the information that repeats across items - resides at a higher level of complexity than simple perceptual features, such as semantic gist, older adults should be less impacted by such interference than young adults. We tested these predictions using the Deese-Roediger-McDermott paradigm, by creating feature-level (i.e., perceptual) interference with phonemically/orthographically related word categories, and higher-level associative interference with semantically related word categories. We manipulated category size in order to compare the effect of less versus more interference (i.e., small versus large category size), which served to (1) avoid potential item confounds arising from systematic differences between words belonging to perceptually- versus semantically-related categories, and (2) ensure that any effect of interference was due to information encoded at study, rather than pre-experimentally. Further, we used signal detection theory (SDT) to interpret our data, rather than examining false alarm (FA) rates in isolation. The d' measure derived from SDT avoids contamination of the memory measure by response bias, and lies on an interval scale, allowing memory performance in different conditions to be compared without violating assumptions of the statistical tests. Older participants were relatively more impaired by perceptual interference and less impaired by semantic interference than young adults. This pattern is at odds with many current theories of age-related memory loss, but is in line with the Representational-Hierarchical account.
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18
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Aly M. In sight, in mind. eLife 2018; 7:35663. [PMID: 29493506 PMCID: PMC5832411 DOI: 10.7554/elife.35663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 02/26/2018] [Indexed: 11/13/2022] Open
Abstract
A region of the brain called the perirhinal cortex represents both what things look like and what they mean.
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Affiliation(s)
- Mariam Aly
- Department of Psychology, Columbia University, New York, United States
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19
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Weiss AR, Guo W, Richardson R, Bachevalier J. Intact perceptual ability, but impaired familiarity judgment, after neonatal perirhinal lesions in rhesus macaques. Dev Cogn Neurosci 2017; 28:54-64. [PMID: 29175539 PMCID: PMC5737963 DOI: 10.1016/j.dcn.2017.10.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 10/15/2017] [Accepted: 10/25/2017] [Indexed: 11/06/2022] Open
Abstract
The perirhinal cortex is known to support high-level perceptual abilities as well as familiarity judgments that may affect recognition memory. We tested whether poor perceptual abilities or a loss of familiarity judgment contributed to the recognition memory impairments reported earlier in monkeys with PRh lesions received in infancy (Neo-PRh) (Weiss and Bachevalier, 2016; Zeamer et al., 2015). Perceptual abilities were assessed using a version of the Visual Paired Comparison task with black&white (B&W) stimuli, and familiarity judgments were assessed using the Constant Negative task requiring repeated familiarization exposures. Adult monkeys with Neo-PRh lesions were able to recognize B&W stimuli after short delays, suggesting that their perceptual abilities were within the range of control animals. However, the same Neo-PRh monkeys were slower to acquire the Constant Negative task, requiring more exposures to objects before judging them as familiar compared to control animals. Taken together, the data help to account for the differential patterns of functional compensation on previously reported recognition tasks following neonatal versus adult-onset PRh lesions, and provide further support to the view that the PRh is involved in familiarity processes.
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Affiliation(s)
| | - Wendi Guo
- Emory University, Atlanta, GA, 30322 USA
| | | | - Jocelyne Bachevalier
- Emory University, Atlanta, GA, 30322 USA; Yerkes National Primate Research Center, Atlanta, GA, 30329 USA
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20
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Neuropsychological Investigations of Human Amnesia: Insights Into the Role of the Medial Temporal Lobes in Cognition. J Int Neuropsychol Soc 2017; 23:732-740. [PMID: 29198269 DOI: 10.1017/s1355617717000649] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The past 30 years of research on human amnesia has yielded important changes in our understanding of the role of the medial temporal lobes (MTL) in memory. On the one hand, this body of evidence has highlighted that not all types of memory are impaired in patients with MTL lesions. On the other hand, this research has made apparent that the role of the MTL extends beyond the domain of long-term memory, to include working memory, perception, and future thinking. In this article, we review the discoveries and controversies that have characterized this literature and that set the stage for a new conceptualization of the role of the MTL in cognition. This shift toward a more nuanced understanding of MTL function has direct relevance for a range of clinical disorders in which the MTL is implicated, potentially shaping not only theoretical understanding but also clinical practice. (JINS, 2017, 23, 732-740).
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21
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Cacciamani L, Wager E, Peterson MA, Scalf PE. Age-Related Changes in Perirhinal Cortex Sensitivity to Configuration and Part Familiarity and Connectivity to Visual Cortex. Front Aging Neurosci 2017; 9:291. [PMID: 28966591 PMCID: PMC5605556 DOI: 10.3389/fnagi.2017.00291] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 08/24/2017] [Indexed: 02/04/2023] Open
Abstract
The perirhinal cortex (PRC) is a medial temporal lobe (MTL) structure known to be involved in assessing whether an object is familiar (i.e., meaningful) or novel. Recent evidence shows that the PRC is sensitive to the familiarity of both whole object configurations and their parts, and suggests the PRC may modulate part familiarity responses in V2. Here, using functional magnetic resonance imaging (fMRI), we investigated age-related decline in the PRC's sensitivity to part/configuration familiarity and assessed its functional connectivity to visual cortex in young and older adults. Participants categorized peripherally presented silhouettes as familiar ("real-world") or novel. Part/configuration familiarity was manipulated via three silhouette configurations: Familiar (parts/configurations familiar), Control Novel (parts/configurations novel), and Part-Rearranged Novel (parts familiar, configurations novel). "Real-world" judgments were less accurate than "novel" judgments, although accuracy did not differ between age groups. The fMRI data revealed differential neural activity, however: In young adults, a linear pattern of activation was observed in left hemisphere (LH) PRC, with Familiar > Control Novel > Part-Rearranged Novel. Older adults did not show this pattern, indicating age-related decline in the PRC's sensitivity to part/configuration familiarity. A functional connectivity analysis revealed a significant coupling between the PRC and V2 in the LH in young adults only. Older adults showed a linear pattern of activation in the temporopolar cortex (TPC), but no evidence of TPC-V2 connectivity. This is the first study to demonstrate age-related decline in the PRC's representations of part/configuration familiarity and its covariance with visual cortex.
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Affiliation(s)
- Laura Cacciamani
- Department of Psychology and Child Development, California Polytechnic State UniversitySan Luis Obispo, CA, United States
| | - Erica Wager
- Department of Psychology, University of ArizonaTucson, AZ, United States
| | - Mary A. Peterson
- Department of Psychology, University of ArizonaTucson, AZ, United States
- Cognitive Science Program, University of ArizonaTucson, AZ, United States
| | - Paige E. Scalf
- Department of Psychology, Durham UniversityDurham, United Kingdom
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22
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Folstein JR, Monfared SS, Maravel T. The effect of category learning on visual attention and visual representation. Psychophysiology 2017; 54:1855-1871. [DOI: 10.1111/psyp.12966] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 06/21/2017] [Accepted: 06/27/2017] [Indexed: 11/27/2022]
Affiliation(s)
| | | | - Trevor Maravel
- Department of Biology; Florida State University; Tallahassee Florida USA
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23
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Cacciamani L, Likova LT. Memory-guided drawing training increases Granger causal influences from the perirhinal cortex to V1 in the blind. Neurobiol Learn Mem 2017; 141:101-107. [PMID: 28347878 PMCID: PMC5488874 DOI: 10.1016/j.nlm.2017.03.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 03/14/2017] [Accepted: 03/23/2017] [Indexed: 10/19/2022]
Abstract
The perirhinal cortex (PRC) is a medial temporal lobe structure that has been implicated in not only visual memory in the sighted, but also tactile memory in the blind (Cacciamani & Likova, 2016). It has been proposed that, in the blind, the PRC may contribute to modulation of tactile memory responses that emerge in low-level "visual" area V1 as a result of training-induced cortical reorganization (Likova, 2012, 2015). While some studies in the sighted have indicated that the PRC is indeed structurally and functionally connected to the visual cortex (Clavagnier, Falchier, & Kennedy, 2004; Peterson, Cacciamani, Barense, & Scalf, 2012), the PRC's direct modulation of V1 is unknown-particularly in those who lack the visual input that typically stimulates this region. In the present study, we tested Likova's PRC modulation hypothesis; specifically, we used fMRI to assess the PRC's Granger causal influence on V1 activation in the blind during a tactile memory task. To do so, we trained congenital and acquired blind participants on a unique memory-guided drawing technique previously shown to result in V1 reorganization towards tactile memory representations (Likova, 2012). The tasks (20s each) included: tactile exploration of raised line drawings of faces and objects, tactile memory retrieval via drawing, and a scribble motor/memory control. FMRI before and after a week of the Cognitive-Kinesthetic training on these tasks revealed a significant increase in PRC-to-V1 Granger causality from pre- to post-training during the memory drawing task, but not during the motor/memory control. This increase in causal connectivity indicates that the training strengthened the top-down modulation of visual cortex from the PRC. This is the first study to demonstrate enhanced directed functional connectivity from the PRC to the visual cortex in the blind, implicating the PRC as a potential source of the reorganization towards tactile representations that occurs in V1 in the blind brain (Likova, 2012).
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Affiliation(s)
- Laura Cacciamani
- The Smith-Kettlewell Eye Research Institute, 2318 Fillmore St., San Francisco, CA 94114, USA.
| | - Lora T Likova
- The Smith-Kettlewell Eye Research Institute, 2318 Fillmore St., San Francisco, CA 94114, USA
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24
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Hernandez AR, Reasor JE, Truckenbrod LM, Lubke KN, Johnson SA, Bizon JL, Maurer AP, Burke SN. Medial prefrontal-perirhinal cortical communication is necessary for flexible response selection. Neurobiol Learn Mem 2016; 137:36-47. [PMID: 27815215 DOI: 10.1016/j.nlm.2016.10.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 10/20/2016] [Accepted: 10/24/2016] [Indexed: 10/20/2022]
Abstract
The ability to use information from the physical world to update behavioral strategies is critical for survival across species. The prefrontal cortex (PFC) supports behavioral flexibility; however, exactly how this brain structure interacts with sensory association cortical areas to facilitate the adaptation of response selection remains unknown. Given the role of the perirhinal cortex (PER) in higher-order perception and associative memory, the current study evaluated whether PFC-PER circuits are critical for the ability to perform biconditional object discriminations when the rule for selecting the rewarded object shifted depending on the animal's spatial location in a 2-arm maze. Following acquisition to criterion performance on an object-place paired association task, pharmacological blockade of communication between the PFC and PER significantly disrupted performance. Specifically, the PFC-PER disconnection caused rats to regress to a response bias of selecting an object on a particular side regardless of its identity. Importantly, the PFC-PER disconnection did not interfere with the capacity to perform object-only or location-only discriminations, which do not require the animal to update a response rule across trials. These findings are consistent with a critical role for PFC-PER circuits in rule shifting and the effective updating of a response rule across spatial locations.
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Affiliation(s)
- Abbi R Hernandez
- McKnight Brain Institute, Department of Neuroscience, University of Florida, United States
| | - Jordan E Reasor
- McKnight Brain Institute, Department of Neuroscience, University of Florida, United States
| | - Leah M Truckenbrod
- McKnight Brain Institute, Department of Neuroscience, University of Florida, United States
| | - Katelyn N Lubke
- McKnight Brain Institute, Department of Neuroscience, University of Florida, United States; Department of Biomedical Engineering, University of Florida, United States
| | - Sarah A Johnson
- McKnight Brain Institute, Department of Neuroscience, University of Florida, United States
| | - Jennifer L Bizon
- McKnight Brain Institute, Department of Neuroscience, University of Florida, United States
| | - Andrew P Maurer
- McKnight Brain Institute, Department of Neuroscience, University of Florida, United States; Department of Biomedical Engineering, University of Florida, United States
| | - Sara N Burke
- McKnight Brain Institute, Department of Neuroscience, University of Florida, United States; Institute on Aging, University of Florida, United States
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25
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Faw M, Faw B. Neurotypical subjective experience is caused by a hippocampal simulation. WILEY INTERDISCIPLINARY REVIEWS. COGNITIVE SCIENCE 2016; 8. [DOI: 10.1002/wcs.1412] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 07/08/2016] [Accepted: 07/19/2016] [Indexed: 12/30/2022]
Affiliation(s)
| | - Bill Faw
- Brewton‐Parker CollegeMt. VernonGAUSA
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26
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Behrmann M, Lee A, Geskin J, Graham K, Barense M. Temporal lobe contribution to perceptual function: A tale of three patient groups. Neuropsychologia 2016; 90:33-45. [DOI: 10.1016/j.neuropsychologia.2016.05.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 04/08/2016] [Accepted: 05/02/2016] [Indexed: 11/29/2022]
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27
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Newsome RN, Duarte A, Pun C, Smith VM, Ferber S, Barense MD. A retroactive spatial cue improved VSTM capacity in mild cognitive impairment and medial temporal lobe amnesia but not in healthy older adults. Neuropsychologia 2015; 77:148-57. [PMID: 26300388 DOI: 10.1016/j.neuropsychologia.2015.08.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 07/30/2015] [Accepted: 08/19/2015] [Indexed: 11/19/2022]
Abstract
Visual short-term memory (VSTM) is a vital cognitive ability, connecting visual input with conscious awareness. VSTM performance declines with mild cognitive impairment (MCI) and medial temporal lobe (MTL) amnesia. Many studies have shown that providing a spatial retrospective cue ("retrocue") improves VSTM capacity estimates for healthy young adults. However, one study has demonstrated that older adults are unable to use a retrocue to inhibit irrelevant items from memory. It is unknown whether patients with MCI and MTL amnesia will be able to use a retrocue to benefit their memory. We administered a retrocue and a baseline (simultaneous cue, "simucue") task to young adults, older adults, MCI patients, and MTL cases. Consistent with previous findings, young adults showed a retrocue benefit, whereas healthy older adults did not. In contrast, both MCI patients and MTL cases showed a retrocue benefit--the use of a retrocue brought patient performance up to the level of age-matched controls. We speculate that the patients were able to use the spatial information from the retrocue to reduce interference and facilitate binding items to their locations.
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Affiliation(s)
- Rachel N Newsome
- Department of Psychology, University of Toronto, 100 St. George Street, Toronto, Ont., Canada M5S 3G3.
| | - Audrey Duarte
- School of Psychology, Georgia Institute of Technology, Atlanta, GA, USA
| | - Carson Pun
- Department of Psychology, University of Toronto, 100 St. George Street, Toronto, Ont., Canada M5S 3G3
| | - Victoria M Smith
- Department of Psychology, University of Toronto, 100 St. George Street, Toronto, Ont., Canada M5S 3G3
| | - Susanne Ferber
- Department of Psychology, University of Toronto, 100 St. George Street, Toronto, Ont., Canada M5S 3G3; Rotman Research Institute, Toronto, Ont., Canada
| | - Morgan D Barense
- Department of Psychology, University of Toronto, 100 St. George Street, Toronto, Ont., Canada M5S 3G3; Rotman Research Institute, Toronto, Ont., Canada
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28
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Erez J, Cusack R, Kendall W, Barense MD. Conjunctive Coding of Complex Object Features. Cereb Cortex 2015; 26:2271-2282. [PMID: 25921583 DOI: 10.1093/cercor/bhv081] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Critical to perceiving an object is the ability to bind its constituent features into a cohesive representation, yet the manner by which the visual system integrates object features to yield a unified percept remains unknown. Here, we present a novel application of multivoxel pattern analysis of neuroimaging data that allows a direct investigation of whether neural representations integrate object features into a whole that is different from the sum of its parts. We found that patterns of activity throughout the ventral visual stream (VVS), extending anteriorly into the perirhinal cortex (PRC), discriminated between the same features combined into different objects. Despite this sensitivity to the unique conjunctions of features comprising objects, activity in regions of the VVS, again extending into the PRC, was invariant to the viewpoints from which the conjunctions were presented. These results suggest that the manner in which our visual system processes complex objects depends on the explicit coding of the conjunctions of features comprising them.
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Affiliation(s)
- Jonathan Erez
- Department of Psychology, University of Toronto, Toronto, ON, CanadaM5S 3G3
| | - Rhodri Cusack
- Department of Psychology, University of Western Ontario, London, ON, Canada N6A 5C2.,The Brain and Mind Institute, London, ON, Canada N6A 5B7
| | - William Kendall
- Department of Psychology, University of British Columbia, Vancouver, BC, CanadaV6T 1Z4
| | - Morgan D Barense
- Department of Psychology, University of Toronto, Toronto, ON, Canada M5S 3G3.,Rotman Research Institute, Toronto, ON, Canada M6A 2E1
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29
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Hales JB, Broadbent NJ, Velu PD, Squire LR, Clark RE. Hippocampus, perirhinal cortex, and complex visual discriminations in rats and humans. ACTA ACUST UNITED AC 2015; 22:83-91. [PMID: 25593294 PMCID: PMC4341362 DOI: 10.1101/lm.035840.114] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Structures in the medial temporal lobe, including the hippocampus and perirhinal cortex, are known to be essential for the formation of long-term memory. Recent animal and human studies have investigated whether perirhinal cortex might also be important for visual perception. In our study, using a simultaneous oddity discrimination task, rats with perirhinal lesions were impaired and did not exhibit the normal preference for exploring the odd object. Notably, rats with hippocampal lesions exhibited the same impairment. Thus, the deficit is unlikely to illuminate functions attributed specifically to perirhinal cortex. Both lesion groups were able to acquire visual discriminations involving the same objects used in the oddity task. Patients with hippocampal damage or larger medial temporal lobe lesions were intact in a similar oddity task that allowed participants to explore objects quickly using eye movements. We suggest that humans were able to rely on an intact working memory capacity to perform this task, whereas rats (who moved slowly among the objects) needed to rely on long-term memory.
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Affiliation(s)
- Jena B Hales
- Department of Psychiatry, University of California, San Diego, La Jolla, California 92093, USA Department of Neurosciences, University of California, San Diego, La Jolla, California 92093, USA
| | - Nicola J Broadbent
- Department of Psychiatry, University of California, San Diego, La Jolla, California 92093, USA
| | - Priya D Velu
- Department of Neurosciences, University of California, San Diego, La Jolla, California 92093, USA
| | - Larry R Squire
- Department of Psychiatry, University of California, San Diego, La Jolla, California 92093, USA Department of Psychology, University of California, San Diego, La Jolla, California 92093, USA Department of Neurosciences, University of California, San Diego, La Jolla, California 92093, USA Veterans Affairs San Diego Healthcare System, San Diego, California 92161, USA
| | - Robert E Clark
- Department of Psychiatry, University of California, San Diego, La Jolla, California 92093, USA Veterans Affairs San Diego Healthcare System, San Diego, California 92161, USA
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Catherwood D, Edgar GK, Nikolla D, Alford C, Brookes D, Baker S, White S. Mapping brain activity during loss of situation awareness: an EEG investigation of a basis for top-down influence on perception. HUMAN FACTORS 2014; 56:1428-1452. [PMID: 25509823 DOI: 10.1177/0018720814537070] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVE The objective was to map brain activity during early intervals in loss of situation awareness (SA) to examine any co-activity in visual and high-order regions, reflecting grounds for top-down influences on Level I SA. BACKGROUND Behavioral and neuroscience evidence indicates that high-order brain areas can engage before perception is complete. Inappropriate top-down messages may distort perception during loss of SA. Evidence of co-activity of perceptual and high-order regions would not confirm such influence but may reflect a basis for it. METHOD SA and bias were measured using Quantitative Analysis of Situation Awareness and brain activity recorded with 128-channel EEG (electroencephalography) during loss of SA. One task (15 participants) required identification of a target pattern, and another task (10 participants) identification of "threat" in urban scenes. In both, the target was changed without warning, enforcing loss of SA. Key regions of brain activity were identified using source localization with standardized low-resolution electrical tomography (sLORETA) 150 to 160 ms post-stimulus onset in both tasks and also 100 to 110 ms in the second task. RESULTS In both tasks, there was significant loss of SA and bias shift (p < .02), associated at both 150- and 100-ms intervals with co-activity of visual regions and prefrontal, anterior cingulate and parietal regions linked to cognition under uncertainty. CONCLUSION There was early co-activity in high- order and visual perception regions that may provide a basis for top-down influence on perception. APPLICATION Co-activity in high- and low-order brain regions may explain either beneficial or disruptive top-down influence on perception affecting Level I SA in real-world operations.
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Abstract
Novelty modulates sensory and reward processes, but it remains unknown how these effects interact, i.e., how the visual effects of novelty are related to its motivational effects. A widespread hypothesis, based on findings that novelty activates reward-related structures, is that all the effects of novelty are explained in terms of reward. According to this idea, a novel stimulus is by default assigned high reward value and hence high salience, but this salience rapidly decreases if the stimulus signals a negative outcome. Here we show that, contrary to this idea, novelty affects visual salience in the monkey lateral intraparietal area (LIP) in ways that are independent of expected reward. Monkeys viewed peripheral visual cues that were novel or familiar (received few or many exposures) and predicted whether the trial will have a positive or a negative outcome--i.e., end in a reward or a lack of reward. We used a saccade-based assay to detect whether the cues automatically attracted or repelled attention from their visual field location. We show that salience--measured in saccades and LIP responses--was enhanced by both novelty and positive reward associations, but these factors were dissociable and habituated on different timescales. The monkeys rapidly recognized that a novel stimulus signaled a negative outcome (and withheld anticipatory licking within the first few presentations), but the salience of that stimulus remained high for multiple subsequent presentations. Therefore, novelty can provide an intrinsic bonus for attention that extends beyond the first presentation and is independent of physical rewards.
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Rosenbaum RS, Gilboa A, Moscovitch M. Case studies continue to illuminate the cognitive neuroscience of memory. Ann N Y Acad Sci 2014; 1316:105-33. [DOI: 10.1111/nyas.12467] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- R. Shayna Rosenbaum
- Department of Psychology; York University; Toronto Ontario Canada
- Rotman Research Institute; Baycrest; Toronto Ontario Canada
- Canadian Partnership in Stroke Recovery, Baycrest; Toronto Ontario Canada
| | - Asaf Gilboa
- Rotman Research Institute; Baycrest; Toronto Ontario Canada
- Canadian Partnership in Stroke Recovery, Baycrest; Toronto Ontario Canada
- Department of Psychology; University of Toronto; Toronto Ontario Canada
| | - Morris Moscovitch
- Rotman Research Institute; Baycrest; Toronto Ontario Canada
- Department of Psychology; University of Toronto; Toronto Ontario Canada
- Department of Psychology, Baycrest; Toronto Ontario Canada
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Cacciamani L, Ayars AA, Peterson MA. Spatially rearranged object parts can facilitate perception of intact whole objects. Front Psychol 2014; 5:482. [PMID: 24904495 PMCID: PMC4033907 DOI: 10.3389/fpsyg.2014.00482] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Accepted: 05/02/2014] [Indexed: 11/13/2022] Open
Abstract
The familiarity of an object depends on the spatial arrangement of its parts; when the parts are spatially rearranged, they form a novel, unrecognizable configuration. Yet the same collection of parts comprises both the familiar and novel configuration. Is it possible that the collection of familiar parts activates a representation of the intact familiar configuration even when they are spatially rearranged? We presented novel configurations as primes before test displays that assayed effects on figure-ground perception from memories of intact familiar objects. In our test displays, two equal-area regions shared a central border; one region depicted a portion of a familiar object. Previous research with such displays has shown that participants are more likely to perceive the region depicting a familiar object as the figure and the abutting region as its ground when the familiar object is depicted in its upright orientation rather than upside down. The novel primes comprised either the same or a different collection of parts as the familiar object in the test display (part-rearranged and control primes, respectively). We found that participants were more likely to perceive the familiar region as figure in upright vs. inverted displays following part-rearranged primes but not control primes. Thus, priming with a novel configuration comprising the same familiar parts as the upcoming figure-ground display facilitated orientation-dependent effects of object memories on figure assignment. Similar results were obtained when the spatially rearranged collection of parts was suggested on the groundside of the prime's border, suggesting that familiar parts in novel configurations access the representation of their corresponding intact whole object before figure assignment. These data demonstrate that familiar parts access memories of familiar objects even when they are arranged in a novel configuration.
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Affiliation(s)
| | | | - Mary A Peterson
- Department of Psychology, University of Arizona Tucson, AZ, USA ; Cognitive Science Program, University of Arizona Tucson, AZ, USA
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34
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Craver CF, Kwan D, Steindam C, Rosenbaum RS. Individuals with episodic amnesia are not stuck in time. Neuropsychologia 2014; 57:191-5. [PMID: 24680757 DOI: 10.1016/j.neuropsychologia.2014.03.004] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Revised: 03/10/2014] [Accepted: 03/12/2014] [Indexed: 11/27/2022]
Abstract
The metaphor that individuals with episodic amnesia due to hippocampal damage are "stuck in time" persists in science, philosophy, and everyday life despite mounting evidence that episodic amnesia can spare many central aspects of temporal consciousness. Here we describe some of this evidence, focusing specifically on KC, one of the most thoroughly documented and severe cases of episodic amnesia on record. KC understands the concept of time, knows that it passes, and can orient himself with respect to his personal past and future. He expresses typical attitudes toward his past and future, and he is able to make future-regarding decisions. Theories claiming that the hippocampus plays an essential role in temporal consciousness need to be revised in light of these findings.
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Affiliation(s)
- Carl F Craver
- Philosophy-Neuroscience-Psychology Program, Washington University, 1 Brookings Drive St. Louis, St. Louis, MO 63130, USA.
| | - Donna Kwan
- Department of Psychology, York University, Toronto, ON, Canada M3J 1P3
| | - Chloe Steindam
- Philosophy-Neuroscience-Psychology Program, Washington University, 1 Brookings Drive St. Louis, St. Louis, MO 63130, USA
| | - R Shayna Rosenbaum
- Department of Psychology, York University, Toronto, ON, Canada M3J 1P3; Rotman Research Institute, Baycrest, Toronto, ON, Canada M6A 2E1
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McLelland VC, Chan D, Ferber S, Barense MD. Stimulus familiarity modulates functional connectivity of the perirhinal cortex and anterior hippocampus during visual discrimination of faces and objects. Front Hum Neurosci 2014; 8:117. [PMID: 24624075 PMCID: PMC3941039 DOI: 10.3389/fnhum.2014.00117] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 02/17/2014] [Indexed: 11/13/2022] Open
Abstract
Recent research suggests that the medial temporal lobe (MTL) is involved in perception as well as in declarative memory. Amnesic patients with focal MTL lesions and semantic dementia patients showed perceptual deficits when discriminating faces and objects. Interestingly, these two patient groups showed different profiles of impairment for familiar and unfamiliar stimuli. For MTL amnesics, the use of familiar relative to unfamiliar stimuli improved discrimination performance. By contrast, patients with semantic dementia—a neurodegenerative condition associated with anterolateral temporal lobe damage—showed no such facilitation from familiar stimuli. Given that the two patient groups had highly overlapping patterns of damage to the perirhinal cortex, hippocampus, and temporal pole, the neuroanatomical substrates underlying their performance discrepancy were unclear. Here, we addressed this question with a multivariate reanalysis of the data presented by Barense et al. (2011), using functional connectivity to examine how stimulus familiarity affected the broader networks with which the perirhinal cortex, hippocampus, and temporal poles interact. In this study, healthy participants were scanned while they performed an odd-one-out perceptual task involving familiar and novel faces or objects. Seed-based analyses revealed that functional connectivity of the right perirhinal cortex and right anterior hippocampus was modulated by the degree of stimulus familiarity. For familiar relative to unfamiliar faces and objects, both right perirhinal cortex and right anterior hippocampus showed enhanced functional correlations with anterior/lateral temporal cortex, temporal pole, and medial/lateral parietal cortex. These findings suggest that in order to benefit from stimulus familiarity, it is necessary to engage not only the perirhinal cortex and hippocampus, but also a network of regions known to represent semantic information.
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Affiliation(s)
| | - David Chan
- Department of Psychology, University of Toronto Toronto, ON, Canada
| | - Susanne Ferber
- Department of Psychology, University of Toronto Toronto, ON, Canada ; Rotman Research Institute Baycrest, Toronto, ON, Canada
| | - Morgan D Barense
- Department of Psychology, University of Toronto Toronto, ON, Canada ; Rotman Research Institute Baycrest, Toronto, ON, Canada
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36
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Barense MD, Erez J, Ma H, Cusack R. Resources required for processing ambiguous complex features in vision and audition are modality specific. COGNITIVE, AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2014; 14:336-353. [PMID: 24022792 DOI: 10.3758/s13415-013-0207-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Processing multiple complex features to create cohesive representations of objects is an essential aspect of both the visual and auditory systems. It is currently unclear whether these processes are entirely modality specific or whether there are amodal processes that contribute to complex object processing in both vision and audition. We investigated this using a dual-stream target detection task in which two concurrent streams of novel visual or auditory stimuli were presented. We manipulated the degree to which each stream taxed processing conjunctions of complex features. In two experiments, we found that concurrent visual tasks that both taxed conjunctive processing strongly interfered with each other but that concurrent auditory and visual tasks that both taxed conjunctive processing did not. These results suggest that resources for processing conjunctions of complex features within vision and audition are modality specific.
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37
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Knutson AR, Hopkins RO, Squire LR. A pencil rescues impaired performance on a visual discrimination task in patients with medial temporal lobe lesions. Learn Mem 2013; 20:607-10. [PMID: 24129096 PMCID: PMC3799417 DOI: 10.1101/lm.032490.113] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We tested proposals that medial temporal lobe (MTL) structures support not just memory but certain kinds of visual perception as well. Patients with hippocampal lesions or larger MTL lesions attempted to identify the unique object among twin pairs of objects that had a high degree of feature overlap. Patients were markedly impaired under the more difficult task conditions. However, the deficit was fully rescued when patients used a pencil to draw lines between the twin pairs, thereby eliminating the need to hold material in memory as they worked at each display. The perceptual demands of the task were presumably the same with or without this memory aid. Accordingly, the results suggest that the deficit on this and similar tasks, which involve comparisons across stimuli, are better understood in terms of impaired memory rather than impaired perception.
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Affiliation(s)
- Ashley R Knutson
- Veterans Affairs San Diego Healthcare System, San Diego, California 92161, USA
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38
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Yonelinas AP. The hippocampus supports high-resolution binding in the service of perception, working memory and long-term memory. Behav Brain Res 2013; 254:34-44. [PMID: 23721964 PMCID: PMC3773061 DOI: 10.1016/j.bbr.2013.05.030] [Citation(s) in RCA: 229] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2012] [Revised: 05/17/2013] [Accepted: 05/20/2013] [Indexed: 10/26/2022]
Abstract
It is well established that the hippocampus plays a critical role in our ability to recollect past events. A number of recent studies have indicated that the hippocampus may also play a critical role in working memory and perception, but these results have been highly controversial because other similar studies have failed to find evidence for hippocampal involvement. Thus, the precise role that the hippocampus plays in cognition is still debated. In the current paper, I propose that the hippocampus supports the generation and utilization of complex high-resolution bindings that link together the qualitative aspects that make up an event; these bindings are essential for recollection, and they can also contribute to performance across a variety of tasks including perception and working memory. An examination of the existing patient literature provides support for this proposal by showing that hippocampal damage leads to impairments on perception and working memory tasks that require complex high-resolution bindings. Conversely, hippocampal damage is much less likely to lead to impairments on tasks that require only low-resolution or simple associations/relations. The current proposal can be distinguished from earlier accounts of hippocampal function, and it generates a number of novel predictions that can be tested in future studies.
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Affiliation(s)
- Andrew P Yonelinas
- Department of Psychology, Center for Mind and Brain, University of California, Davis, CA 95616, USA.
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Erez J, Lee ACH, Barense MD. It does not look odd to me: perceptual impairments and eye movements in amnesic patients with medial temporal lobe damage. Neuropsychologia 2012; 51:168-80. [PMID: 23154380 PMCID: PMC3557385 DOI: 10.1016/j.neuropsychologia.2012.11.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Revised: 10/29/2012] [Accepted: 11/02/2012] [Indexed: 12/16/2022]
Abstract
Studies of people with memory impairments have shown that a specific set of brain structures in the medial temporal lobe (MTL) is vital for memory function. However, whether these structures have a role outside of memory remains contentious. Recent studies of amnesic patients with damage to two structures within the MTL, the hippocampus and the perirhinal cortex, indicated that these patients also performed poorly on perceptual tasks. More specifically, they performed worse than controls when discriminating between objects, faces and scenes with overlapping features. In order to investigate whether these perceptual deficits are reflected in their viewing strategies, we tested a group of amnesic patients with MTL damage that included the hippocampus and perirhinal cortex on a series of oddity discrimination tasks in which they had to select an odd item from a visual array. Participants' eye movements were monitored throughout the experiment. Results revealed that patients were impaired on tasks that required them to discriminate between items that shared many features, and tasks that required processing items from different viewpoints. An analysis of their eye movements revealed that they exhibited a similar viewing pattern as controls: they fixated more on the target item on trials answered correctly, but not on trials answered incorrectly. In addition, their impaired performance was not explained by an abnormal viewing-strategy that assessed their use of working memory. These results suggest that the perceptual deficits in the MTL patients are not a consequence of abnormal viewing patterns of the objects and scenes, but instead, could involve an inability to bind information gathered from several fixations into a cohesive percept. These data also support the view that MTL structures are important not only for long-term memory, but are also involved in perceptual tasks.
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Affiliation(s)
- Jonathan Erez
- Department of Psychology (St. George), University of Toronto, Toronto, ON, Canada M5S 3G3.
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40
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Competition-strength-dependent ground suppression in figure-ground perception. Atten Percept Psychophys 2012; 74:964-78. [PMID: 22391891 DOI: 10.3758/s13414-012-0280-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Figure-ground segregation is modeled as inhibitory competition between objects that might be perceived on opposite sides of borders. The winner is the figure; the loser is suppressed, and its location is perceived as shapeless ground. Evidence of ground suppression would support inhibitory competition models and would contribute to explaining why grounds are shapeless near borders shared with figures, yet such evidence is scarce. We manipulated whether competition from potential objects on the ground side of figures was high (i.e., portions of familiar objects were potentially present there) or low (novel objects were potentially present). We predicted that greater competition would produce more ground suppression. The results of two experiments in which suppression was assessed via judgments of the orientation of target bars confirmed this prediction; a third experiment showed that ground suppression is short-lived. Our findings support inhibitory competition models of figure assignment, in particular, and models of visual perception entailing feedback, in general.
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41
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Ryan L, Cardoza JA, Barense MD, Kawa KH, Wallentin-Flores J, Arnold WT, Alexander GE. Age-related impairment in a complex object discrimination task that engages perirhinal cortex. Hippocampus 2012; 22:1978-89. [PMID: 22987676 PMCID: PMC4512648 DOI: 10.1002/hipo.22069] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Previous lesion studies have shown compromised complex object discrimination in rats, monkeys, and human patients with damage to the perirhinal cortical region (PRC) of the medial temporal lobe. These findings support the notion that the PRC is involved in object discrimination when pairs of objects have a high degree of overlapping features but not when object discrimination can be resolved on the basis of a single feature (e.g., size or color). Recent studies have demonstrated age-related functional changes to the PRC in animals (rats and monkeys) resulting in impaired complex object discrimination and object recognition. To date, no studies have compared younger and older humans using paradigms previously shown to engage the PRC. To investigate the influence of age on complex object discrimination in humans, the present study used an object matching paradigm for blob-like objects that have previously been shown to recruit the PRC. Difficulty was manipulated by varying the number of overlapping features between objects. Functional MRI data was acquired to determine the involvement of the PRC in the two groups during complex object discrimination. Results indicated that while young and older adults performed similarly on the easy version of the task, most older adults were impaired relative to young participants when the number of overlapping features increased. fMRI results suggest that older adults do not engage bilateral anterior PRC to the same extent as young adults. Specifically, complex object matching performance in older adults was predicted by the degree to which they engage left anterior PRC. These results provide evidence for human age-related changes in PRC function that impact complex object discrimination.
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Affiliation(s)
- L Ryan
- Department of Psychology, Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ 85721, USA.
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Barense MD, Groen IIA, Lee ACH, Yeung LK, Brady SM, Gregori M, Kapur N, Bussey TJ, Saksida LM, Henson RNA. Intact memory for irrelevant information impairs perception in amnesia. Neuron 2012; 75:157-67. [PMID: 22794269 PMCID: PMC3657172 DOI: 10.1016/j.neuron.2012.05.014] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/07/2012] [Indexed: 12/12/2022]
Abstract
Memory and perception have long been considered separate cognitive processes, and amnesia resulting from medial temporal lobe (MTL) damage is thought to reflect damage to a dedicated memory system. Recent work has questioned these views, suggesting that amnesia can result from impoverished perceptual representations in the MTL, causing an increased susceptibility to interference. Using a perceptual matching task for which fMRI implicated a specific MTL structure, the perirhinal cortex, we show that amnesics with MTL damage including the perirhinal cortex, but not those with damage limited to the hippocampus, were vulnerable to object-based perceptual interference. Importantly, when we controlled such interference, their performance recovered to normal levels. These findings challenge prevailing conceptions of amnesia, suggesting that effects of damage to specific MTL regions are better understood not in terms of damage to a dedicated declarative memory system, but in terms of impoverished representations of the stimuli those regions maintain.
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Affiliation(s)
- Morgan D Barense
- Department of Psychology University of Toronto, Toronto, ON, Canada.
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43
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Rudebeck SR, Filippini N, Lee ACH. Can complex visual discrimination deficits in amnesia be attributed to the medial temporal lobe? An investigation into the effects of medial temporal lobe damage on brain connectivity. Hippocampus 2012; 23:7-13. [PMID: 23233411 PMCID: PMC3555392 DOI: 10.1002/hipo.22056] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2012] [Indexed: 11/09/2022]
Abstract
It has been suggested that complex visual discrimination deficits in patients with medial temporal lobe (MTL) damage may be explained by damage or dysfunction beyond the MTL. We examined the resting functional networks and white matter connectivity of two amnesic patients who have consistently demonstrated discrimination impairments for complex object and/or spatial stimuli across a number of studies. Although exploratory analyses revealed some significant differences in comparison with neurologically healthy controls (more specifically in the patient with a larger MTL lesion), there were no obvious findings involving posterior occipital or posterior temporal regions, which can account entirely for their discrimination deficits. These findings converge with previous work to support the suggestion that the MTL does not subserve long-term declarative memory exclusively.
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Affiliation(s)
- Sarah R Rudebeck
- Department of Experimental Psychology, University of Oxford, United Kingdom
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44
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Visual discrimination performance, memory, and medial temporal lobe function. Proc Natl Acad Sci U S A 2012; 109:13106-11. [PMID: 22826243 DOI: 10.1073/pnas.1208876109] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We evaluated recent proposals that structures in the medial temporal lobe (MTL)--in particular, perirhinal cortex--support not just memory but certain kinds of perceptual abilities as well. Specifically, it has been suggested that the perirhinal cortex supports the perceptual abilities needed to accomplish visual discrimination performance when the stimuli have complex features and overlapping elements. However, the tasks that have been studied are quite challenging. Stimulus features must be held in working memory while attention shifts among the several parts of the display. When working memory capacity is exceeded, performance must depend on retrieval from long-term memory. Five patients with limited hippocampal lesions and one patient with large MTL lesions were asked to identify the unique object among twin pairs of objects that had a high degree of feature overlap and perceptual similarity. The patient groups performed similarly to controls when there were few objects and features in the displays, but exhibited abrupt declines in performance when the displays contained more objects and more features. Notably, the impairment was observed in memory-impaired patients with hippocampal lesions, not only in association with large MTL lesions that included perirhinal cortex. The pattern of performance suggested that patients encountered difficulty because working memory capacity was exceeded in the more difficult conditions such that performance needed to depend at least in part on long-term memory. Furthermore, when the burden on working memory was removed entirely, the patient with large MTL lesions performed as well as controls. Accordingly, we suggest that deficits on difficult discrimination tasks reported for patients with MTL lesions are due to impaired memory rather than impaired perception.
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45
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Lee ACH, Yeung LK, Barense MD. The hippocampus and visual perception. Front Hum Neurosci 2012; 6:91. [PMID: 22529794 PMCID: PMC3328126 DOI: 10.3389/fnhum.2012.00091] [Citation(s) in RCA: 136] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2011] [Accepted: 03/30/2012] [Indexed: 11/15/2022] Open
Abstract
In this review, we will discuss the idea that the hippocampus may be involved in both memory and perception, contrary to theories that posit functional and neuroanatomical segregation of these processes. This suggestion is based on a number of recent neuropsychological and functional neuroimaging studies that have demonstrated that the hippocampus is involved in the visual discrimination of complex spatial scene stimuli. We argue that these findings cannot be explained by long-term memory or working memory processing or, in the case of patient findings, dysfunction beyond the medial temporal lobe (MTL). Instead, these studies point toward a role for the hippocampus in higher-order spatial perception. We suggest that the hippocampus processes complex conjunctions of spatial features, and that it may be more appropriate to consider the representations for which this structure is critical, rather than the cognitive processes that it mediates.
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Affiliation(s)
- Andy C H Lee
- Department of Psychology (Scarborough), University of Toronto, Toronto ON, Canada
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Nadel L, Hupbach A, Gomez R, Newman-Smith K. Memory formation, consolidation and transformation. Neurosci Biobehav Rev 2012; 36:1640-5. [PMID: 22465050 DOI: 10.1016/j.neubiorev.2012.03.001] [Citation(s) in RCA: 173] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 02/20/2012] [Accepted: 03/02/2012] [Indexed: 11/16/2022]
Abstract
Memory formation is a highly dynamic process. In this review we discuss traditional views of memory and offer some ideas about the nature of memory formation and transformation. We argue that memory traces are transformed over time in a number of ways, but that understanding these transformations requires careful analysis of the various representations and linkages that result from an experience. These transformations can involve: (1) the selective strengthening of only some, but not all, traces as a function of synaptic rescaling, or some other process that can result in selective survival of some traces; (2) the integration (or assimilation) of new information into existing knowledge stores; (3) the establishment of new linkages within existing knowledge stores; and (4) the up-dating of an existing episodic memory. We relate these ideas to our own work on reconsolidation to provide some grounding to our speculations that we hope will spark some new thinking in an area that is in need of transformation.
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Affiliation(s)
- L Nadel
- Department of Psychology, University of Arizona, United States.
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