Brain reserve theory: Are adults with intellectual disability more vulnerable to age than peers with typical development?

BACKGROUND

Life expectancy is on rise and the intriguing question is: When does cognitive decline occur among adults with intellectual disability, compared to adults with typical development? This cross-sectional study examined cognitive performance of crystallised/fluid intelligence, working and long-term memory of adults with intellectual disability of etiologies other than Down syndrome (IQ 50-68) and adults with typical development (IQ 85-114) in four age cohorts (30-39; 40-49; 50-59; 60-69).

METHOD

The WAIS III^HEB and the Rey-AVLT were administered to both groups.

RESULTS

Four patterns of cognitive performance were found: (a) Vocabulary (crystallised intelligence), Spatial Span Forward and Retention yielded similar scores across all four age cohorts in participants with typical development and with intellectual disability. (b) Similarities, Raven and Digit Span Backward exhibit lower scores only in 50-59 or 60-69 compared to the 30-39 age cohort in both groups, (c) Digit Span Forward, Spatial Span Backward and Total Leaning (LTM) yielded lower scores in the 50-59 or 60-69 age cohorts in the typical group, but similar scores in participants with intellectual disability along the age cohorts, (d) Block Design (fluid intelligence) yielded a lower score in the 50-59 cohort versus lower scores only at ages 60-69 in participants with typical development.

CONCLUSIONS

Our findings suggest a possible parallel trajectory in age-related cognitive performance for individuals with and without intellectual disability in six measures, and a possible more preserved trajectory in fluid intelligence and some memory measures in adults with intellectual disability compared to their peers. Caution should be exercised regarding Digit and Spatial Span Backwards, which yielded a floor effect in participants with intellectual disability. The Cognitive Reserve Theory, the Safeguard Hypothesis and late maturation might serve as explanations for these findings.

The benefit of assessing implicit sequence learning in pianists with an eye-tracked serial reaction time task

Playing piano professionally has been shown to benefit implicit motor sequence learning. The aim of the current study was to determine whether this advantage reflects generally enhanced implicit sequence learning unrelated to pianists' higher motor and/or visual-motor coordination abilities. We examined implicit sequence learning using the ocular serial reaction time (O-SRT) task, a manual-free eye-tracked version of the standard SRT, in 29 pianists and 31 controls. Reaction times (RT) and correct anticipations (CA) of several phases describing implicit sequence learning were analyzed. Furthermore, explicit sequence knowledge was compared between the groups, and relationships between implicit sequence learning with explicit sequence knowledge or demographic measures were evaluated. Pianists demonstrated superiority in all critical phases of implicit sequence learning (RT and CA). Moreover, pianists acquired higher explicit sequence knowledge, and only in pianists was explicit sequence knowledge related to implicit sequence learning. Our results demonstrate that pianists' superiority in implicit sequence learning is due to a higher general implicit sequence learning ability. Hence, we can exclude that higher motor and/or visual-motor coordination abilities are related to pianists' higher implicit sequence learning. Furthermore, the significant relationship of implicit sequence learning and explicit sequence knowledge suggests that pianists either used explicit strategies to support implicit sequence learning, had better explicit access to sequence knowledge, or both.

Life span strategy implementation in verbal learning: size and type of cluster adoption

Temporal and semantic associative processes during the acquisition of new verbal information undergo various changes across the life span. Temporal order clusters and subjective clusters were monitored during verbal learning trials using the Rey (Auditory Verbal Learning Task) for 1471 participants aged 8-91. Pairs, three-word, and four-word clusters were measured. Subjective clusters were generated at similar frequency across the whole life span. By contrast, a clear inverted-U curve across life span was indicated for temporal clusters. More words were subjectively clustered than clustered by temporal presentation order. The number of words clustered increased across trials, and cluster types showed a different increase profile across trials. The subjective cluster increment was faster and steeper than the temporal cluster increment in most of the age segments. Life span trajectory tendencies in the formation of temporal and semantic associations in recall were interpreted in relation to different frameworks of cognitive life span changes.

The adapted symbol digit modalities test: Examining the impact of response modality

BACKGROUND

Information processing speed is often impaired in neurological disorders, as well as with healthy aging. Thus, being able to accurately assess information processing speed is of high importance. One of the most commonly used tests to examine information processing speed is the Symbol Digit Modalities Test (SDMT), which has been shown to have good psychometric properties.

OBJECTIVES

The current study aims to examine differences between two response modalities, written and oral, on the performance of an adapted version of the Symbol Digit Modalities Test.

METHODS

Ninety-nine individuals completed two alternate forms of the adapted version of the SDMT (aSDMT). Participants were instructed to complete the five lines of the task as quickly and accurately as possible. On one form participants were instructed to provide their response in writing and on the other one, orally. Form and response modality (oral vs. written) were counterbalanced to control for practice effects.

RESULTS

On average, there was a significant difference between response modalities, such that participants needed more time to respond when the response modality was written. For both response modalities, time to complete each line of stimuli decreased as the task progressed. While changes in response time on the first four lines of stimuli on the oral version were not found, there was a substantial improvement in response time on the fifth line. In contrast, on the written version a gradual learning effect was observed, in which response time was the slowest on the first two lines, an intermediate response time was noted on line 3, and the fastest response time was achieved on lines four and five.

CONCLUSION

The current study demonstrates that response modality, oral versus written, can significantly impact performance efficiency (the length of time it takes to complete a task), but not accuracy (total correct responses), on a new adaptation of the SDMT, the aSDMT.

Day versus night consolidation of implicit sequence learning using manual and oculomotor activation versions of the serial reaction time task: reaction time and anticipation measures

This study presents two experiments that explored consolidation of implicit sequence learning based on two dependent variables-reaction time (RT) and correct anticipations to clarify the role of sleep, and whether the manual component is necessary for consolidation processes. Experiment 1 (n = 37) explored the performance of adults using an ocular variant of the serial reaction time task (O-SRT) with manual activation (MA), and Experiment 2 (n = 37) used the ocular activation (OA) version of the task. Each experiment consisted of a Day and a Night group that performed two sessions of the O-SRT with an intervening 12-h offline period (morning/evening in Day group, evening/following morning in Night group). Night offline had an advantage only when manual response was required and when correct anticipations (i.e., accuracy) but not RT (i.e., speed) were measured. We associated this finding with the dual-learning processes required in the MA O-SRT that led to increased sequence specific learning overnight. When using the OA O-SRT, both groups demonstrated similar rates after offline in RT and correct anticipations. We interpreted this finding to reflect stabilization, which confirmed our hypothesis. As expected, all the groups demonstrated reduced performance when another sequence was introduced, thus reflecting sequence-specific learning. This study used a powerful procedure that allows measurement of implicit sequence learning in several ways: by evaluating two different measures (RT, correct anticipations) and by isolating different aspects of the task (i.e., with/without the manual learning component, more/less general skill learning), which are known to affect learning and consolidation.

Oculomotor anticipation reveals a multitude of learning processes underlying the serial reaction time task

Sequence learning is the cognitive faculty enabling everyday skill acquisition. In the lab, it is typically measured in speed of response to sequential stimuli, whereby faster responses are taken to indicate improved anticipation. However, response speed is an indirect measure of anticipation, that can provide only limited information on underlying processes. As a result, little is known about what is learned during sequence learning, and how that unfolds over time. In this work, eye movements that occurred before targets appeared on screen in an ocular serial reaction time (O-SRT) task provided an online indication of where participants anticipated upcoming targets. When analyzed in the context of the stimuli preceding them, oculomotor anticipations revealed several simultaneous learning processes. These processes influenced each other, as learning the task grammar facilitated acquisition of the target sequence. However, they were dissociable, as the grammar was similarly learned whether a repeating sequence inhabited the task or not. Individual differences were found in how the different learning processes progressed, allowing for similar performance to be produced for different latent reasons. This study provides new insights into the processes subserving sequence learning, and a new method for high-resolution study of it.

Associative recognition memory for identity, spatial and temporal relations in healthy aging

The ability to generate associative representations and to retrieve them from long-term episodic memory generally declines in healthy aging. However, it is unclear whether healthy aging has differential effects on associative memory for identity, spatial configuration, and temporal order relationships. In the current study, we assessed how healthy aging impacts on associative memory for identity, spatial, or temporal relationships between pairs of visual objects via discrimination of intact and rearranged pairs. Accuracy and response time performance of healthy older adults (aged 65-80) were compared with young adults (ages 19-30). Age-related declines in associative memory were observed equally for all types of associations, but these declines differed by associative status: aging most strongly affected ability to discriminate rearranged pairs. These results suggest that associative memory for identity, spatial, and temporal relationships are equally affected by healthy aging, and may all depend on a shared set of basic associative mechanisms.

Implicit sequence learning in individuals with Parkinson's disease: The added value of using an ocular version of the serial reaction time (O-SRT) task

INTRODUCTION

Though the majority of studies reported impaired sequence learning in individuals with Parkinson's disease (PD) tested with the Serial Reaction Time (SRT) task, findings are inconclusive. To elucidate this point, we used an eye tracker in an ocular SRT task version (O-SRT) that in addition to RT, enables extraction of two measures reflecting different cognitive processes, namely, Correct Anticipation (CA) and number of Stucks.

METHODS

Individuals with PD (n = 29) and matched controls (n = 31) were tested with the O-SRT task, consisting of a repeated sequence of six blocks, then a block with an interference sequence followed by an original sequence block.

RESULTS

Unlike controls, patients with PD did not improve in CA rate across learning trials, did not show an increase in RT when presented with the interference sequence, and showed a significantly higher rate of Stucks.

CONCLUSIONS

Low CA rate and high Stucks rate emerge as the cardinal deficits leading to impaired sequence learning following PD. These are viewed as reflecting difficulty in exploration for an efficient learning strategy. This study highlights the advantage in using the O-SRT task, which enables the generation of several informative measures of learning, allowing better characterization of the PD effect on sequence learning.

Selective Procedural Memory Impairment but Preserved Declarative Memory in Spinocerebellar Ataxia Type 3

Spinocerebellar ataxia type 3 (SCA3), also known as Machado-Joseph disease, is an autosomal dominant neurodegenerative disorder that affects mainly the cerebellum and less other brain areas. While the ataxic/motor features of the disease have been well described, the cognitive consequences of the degeneration require additional testing. The aim of this study was to evaluate learning abilities in SCA3. We tested 13 SCA3 patients and 14 age-matched healthy controls, all of Yemenite origin, on a neuropsychological battery of procedural and declarative memory tests. SCA3 patients demonstrated impaired sequence learning on the procedural Serial Reaction Time test (SRTt) but normal learning on the procedural Weather Prediction Probabilistic Classification test (WPPCt). SCA3 patients showed normal learning on the declarative Rey Auditory Verbal Learning test (Rey-AVLt). The correlations between the learning measures of the SRTt, WPPCt, and Rey-AVLt tests in SCA3 and controls separately were not significant. These results imply that the cerebellar degeneration in SCA3 causes selective impairment in procedural sequence learning while the procedural probabilistic learning and declarative memory were mostly preserved. These findings support the assumption that procedural learning is not a homogeneous function and could be dissociated in cerebellar neurodegenerative disease.

New insights in implicit sequence learning of adults with traumatic brain injury: As measured by an ocular serial reaction time (O-SRT) task

Objective: We investigated the effect of traumatic brain injury (TBI) on implicit sequence learning (ISL) and its relation with demographic, clinical, and working memory (WM) capacity using an eye-tracked variant of the standard serial reaction time (RT; SRT) task. Besides RT, this ocular SRT (O-SRT) task enables generation of correct anticipations (CA) and stucks, reflecting other critical aspects of ISL. Method: ISL was tested in 26 individuals with TBI and 28 healthy controls using the O-SRT task. Mixed analyses of variance were conducted to analyze RT and CA in three phases: learning, interference, and recovery from interference. The average number of stucks was compared with an independent-samples t test. Finally, Pearson correlation analyses of ISL with demographic, clinical, and WM capacity measures were performed. Results: Based on RT, ISL was impaired in the TBI group. However, CA demonstrated improved learning, but with deficits in the interference and recovery from interference phases. Stucks were more frequent in the TBI group, which affected RT and CA measures. Neither demographic nor clinical factors were associated with ISL. Verbal, but not spatial, WM capacity was impaired in the TBI group, and spatial WM capacity positively correlated with ISL in controls only. Conclusion: We suggest that the high TBI group stuck rate can be attributed to lack of initiative and/or conservative response bias associated with TBI, and view it as a main cause leading to deficits in ISL. Unlike controls, the TBI group could not muster their relatively preserved spatial WM capacity to support their ISL performance. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

How sequence learning unfolds: Insights from anticipatory eye movements

The acquisition of sequential knowledge is pivotal in forming skilled behavior. Despite extensive research of sequence learning, much remains unknown regarding what knowledge participants learn in such studies, and how that knowledge takes form over time. By tracking eye-movements made before stimuli appear on screen during a serial reaction time (SRT) task, we devised a method for assessing learning at the individual participant level in an item-based resolution. Our method enables uncovering what participants actually learn about the sequence presented to them, and when. Results demonstrate that learning is more heterogeneous than previously thought, driven by learning both of chunks and of statistics embedded in the sequence. Also, learning develops rapidly, but in a fragmented and non-sequential manner, eventually encompassing only a subset of available regularities. The tools developed in this work may aid in further dissociating processes and mechanisms underlying sequence learning and its impairments, in normal and in clinical populations.

Medical Help-Seekers with Anxiety from Deterioration in Memory are Characterized with Risk Factors for Cognitive Decline

Objectives: Anxiety and subjective memory complaints (SMC) are major risk factors for Mild Cognitive Impairment (MCI) and dementia. However, the association between anxiety, SMC and medical help-seeking due to complaints is not clear. Here, we assessed anxiety which rose specifically by memory examination and compared it between help-seekers in memory clinics (HS) and non-help seekers (NHS).Methods: Twenty HS (60% female) were recruited from a memory Clinic, and 55 NHS (63% female) were recruited from the community. Participants (aged 59-82) completed objective memory assessment, Subjective Memory questionnaire, depression questionnaire and State-Trait Anxiety questionnaire. State-anxiety was assessed immediately following memory testing (indicating anxiety triggered by testing memory). For statistical evaluation, we used non-parametric tests.Results: HS participants reported significantly higher levels of state-anxiety and had more SMC compared to the NHS. No differences in objective memory tests and trait-anxiety were found.Conclusions: People who are seeking help in memory clinics (even those who do not meet any criteria for memory decline) are liable to be at high risk for MCI and dementia.Clinical Implications: We recommend that HS with SMC should be treated as a high-risk group, even if they do not show objective memory deficits.

Traumatic brain injury hinders learning of road hazard awareness by repeated exposure to video-based hazards

OBJECTIVE

To better understand hazard awareness abilities among traumatic brain injury (TBI) survivors of which little is currently known. TBI survivors express degradation in driving abilities, particularly the proactive strategy in which indicators of potentially hazardous situations are sought and identified. The current study examined differences in hazard awareness learning between TBI survivors and noninjured control individuals matched for age and driving experience.

METHOD

Forty individuals equally divided among the 2 groups were assessed by exposure to repetitive video-based hazard scenarios, which have been shown to improve hazard awareness in noninjured individuals. Differences in participants' eye movements and behavioral response while watching video clips of genuine traffic scenes were recorded.

RESULTS

Although survivors of TBI demonstrated relatively intact hazard awareness abilities under baseline conditions, they failed to learn from repetitive presentation of the same hazardous situation (i.e., they did not improve hazard detection) and thus failed to adjust their scanning and behavioral reaction (e.g., time to reaction, adapt of scanning behavior). Differences were more prominent for hidden hazards. Our results show impoverished anticipation abilities in driving simulation tasks performed in the subacute recovery phase after TBI and that differences in materialized hazards awareness are distinguishable between TBI survivors and noninjured drivers of similar age and driving experience.

CONCLUSIONS

Our findings signal the need for further research to clarify the relationship between TBI and hazard awareness training that might be supportive of driving rehabilitation after TBI. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Mental Rotation: The Effects of Processing Strategy, Gender and Task Characteristics on Children's Accuracy, Reaction Time and Eye Movements' Pattern

The effects of gender, strategy and task characteristics on children's mental rotation (MR) behavioral measures and eye movements were studied. Eye movements reflect thinking pattern and assist understanding mental rotation performance. Eighty-three fourth-grade children (44 boys and 39 girls) were administered the Computerized Windows Mental Rotation test (CWMR) while having their eye movements monitored and completed a Strategy Self-Report (global/local/combined) and a Spatial Span (WM) subtest. Difficulty level affected performance and was reflected in a different eye movement pattern. Boys were more accurate than girls, but they did not differ in their eye movement pattern. Eye movement pattern was related to strategy, accu-racy and reaction time, revealing that the global and combined strategy were more effective compared with local strategy. WM was found to correlate with accuracy at the easy level of the test. The usage of eye movement measures assists in elaborating our knowledge regarding MR performance among chil-dren and enable a wider understanding regarding the interaction between gender, strategy and difficulty level.

Eye Movement Performance on the Stroop Test in Adults With ADHD

Objective: To compare the eye movement patterns of adults with ADHD with those of controls as they perform the Stroop test. Method: Thirty individuals with ADHD (ages 18-31), and 30 controls participated in this study. The hypothesis was that under the incongruent condition, the group with ADHD would focus longer on the distracter than the controls. Results: Participants with ADHD showed a more pronounced Stroop effect than the controls. Eye movements indicated that more time was spent fixating on the target than on the distracter. The most significant differences between the groups were the overall time spent on the target and the number of fixations on the target, rather than on the distracter. Furthermore, the group with ADHD made more transitions between the target and distracter stimuli. Conclusion: These results were interpreted to indicate an inefficient strategy used by the group with ADHD in their attempt to ignore the distracter stimuli.

Direct and indirect measures of context in patients with mild-to-severe traumatic brain injury (TBI): The additive contribution of eye tracking

Introduction: The facilitation of memory for target stimuli due to the similarity of context in the learning and testing phases is known as the "Context-Effect" (CE). Previous studies reported that TBI affects memory for contextual information when tested directly. However, the indirect effect of contextual information on memory of target (i.e., CE) is preserved. Several studies have demonstrated that CE is composed of multiple, distinct cognitive processes. The present study includes four context conditions to enable identification of the exact process affected by TBI. In addition, eye movements were monitored to test three hypotheses: first, that the TBI group's dwell time on target (DTOT) at encoding would be less than that of controls. Second, that DTOT at encoding would be more highly associated with recognition at test for the control group than for the TBI group. Third, that overall DTOT at encoding on new, as compared to old items ("repetition effect"), would be less pronounced for the TBI group as compared to controls. Methods: Twenty-four patients with mild-to-severe TBI and 23 matched controls participated in this study. We presented participants with photographs of male faces shown wearing distinctive, trial-unique hats (yielding specific Target-Context pairing). Eye movements were recorded throughout the test task. Results: Memory for faces following TBI is impaired compared to that of controls. The magnitude and pattern of CE are the same for both groups. The TBI group has a lower DTOT compared to that of controls. However, the relative length of DTOT in the various conditions is similar in both groups. Conclusions: Behavioral results indicate that although the TBI group has impaired memory for faces, the CE pattern is similar to that of controls. Similarly, in terms of eye movements, although the TBI group focuses less on target, relations between the various conditions are similar in both groups.

Conceptual processes involved in words and scenes context effect in face recognition

Several studies have established the impact of conceptually similar context on the emergence of "Context-Effect" (CE). None of these studies included the Re-pair/rearrange condition at the test, which prevented them from being conclusive about the exact process (binding/ensemble or familiarity) that was affected by the conceptually similar context. To this end, in the present study faces (target to be remembered) were presented in the context of either words (W) or picture (P) scenes, and at test Re-pair was added as one of the context conditions. At test two groups were presented with the same context as in study (consistent condition) (WW & PP), and two groups with the inconsistent condition (WP & PW). Results showed no familiarity effect when only the conceptual match was preserved (i.e., inconsistent condition) and both effects of binding and familiarity when both conceptual and perceptual match were present (i.e., consistent condition). Thus, the semantic association between a face and context could serve as recognition cues even when modality has been changed, but the label remained constant.

The effects of repetitive presentation of specific hazards on eye movements in hazard perception training, of experienced and young-inexperienced drivers

Recent evidence shows that compared to experienced drivers, young-inexperienced drivers are more likely to be involved in a crash mainly due to their poor hazard perception (HP) abilities. This skill develops with experience and may be developed through training. We assumed that as any other skill, HP developed through implicit learning. Nevertheless, current training methods, rely on deliberate learning where young-inexperienced drivers are instructed what hazards that they should seek and where they might be located. In this exploratory study, we investigated the effectiveness of a novel training procedure, in which learners were repeatedly exposed to target video clips of driving scenarios embedded within filler scenarios. Each of the target videos included scenarios of either a visible hazard, a hidden materialized hazard or hidden unmaterialized hazard. Twenty-three young-inexperienced drivers and 35 experienced drivers participated in training session followed by a learning transference testing session and 24 additional young-inexperienced drivers participated only in the transference testing session with no training, during which participants were shown novel hazards video clips. Participants responded by pressing a button when they identified a hazard. Eye movement was also tracked using fixations patterns as a proxy to evaluate HP performance. During training, young-inexperienced drivers gradually increased their focus on visible materialized hazards but exhibited no learning curve with respect to hidden hazards. During the learning transference session, both trained groups focused on hazards earlier compared to untrained drivers. These results imply that repetitive training may facilitate HP acquisition among young-inexperienced drivers. Patterns concerning experienced drivers are also discussed.

Facial expressions yielding Context-Dependent Effect: The additive contribution of eye movements

This study tested Context-Dependent Effect (CDE) on face recognition by viewing facial expressions as context and face identity as the target. Three groups were defined - Neutral, Happy and Angry, reflecting the facial expressions of the faces presented at the study phase. At the study phase, participants were presented with 42 color photos of faces for 5 s each. At the test phase, participants were presented with 84 pictures of faces, half of which had been viewed beforehand (old). One-third of the old and new faces displayed the same facial expression shown at study, and the remaining two-thirds had one of the other two expressions. Behavioral results show that consistency of facial expressions between study and test facilitated face recognition (i.e., CDE). Eye-tracking results showed that lengthier focus on a face at the study phase gives the participant an advantage only when the same face is presented again at the test phase. Angry expressions intensify binding more than happy or neutral expressions, resulting in higher costs when changing facial expression between study and test. The theoretical implications of these results in terms of the relationship between facial identity and facial expression are discussed. The practical implications, particularly for eyewitness memory literature, are also discussed.

The origin of the centrality deficit in individuals with attention-deficit/hyperactivity disorder

INTRODUCTION

Studies have shown that skilled and disabled readers recall central ideas, which are important to the overall comprehension of the text, to a greater extent than peripheral, less important ideas after reading. However, readers with attention-deficit/hyperactivity disorder (ADHD) recall significantly fewer central ideas than skilled readers. The present study was designed to examine whether difficulties in identifying, attending, and/or retrieving central ideas underlie their centrality deficit.

METHOD

28 adult university students with ADHD and 27 control students read three expository texts (successively) to summarize their central ideas, while their eye-movements were recorded. After reading, the participants recalled, recognized, and estimated the centrality level of all text ideas, which were divided into central and peripheral based on pretest ratings.

RESULTS

The participants with ADHD recalled fewer central ideas than controls, although they recognized and estimated their centrality to the same extent as controls. Moreover, the participants with ADHD invested more time in rereading central ideas than peripheral ones, to a greater extent than controls.

CONCLUSIONS

The eye-movement data suggest that our university students with ADHD were aware of the reading task requirements, their difficulties, and the appropriate strategies for coping with them (i.e., rereading central ideas). More importantly, the present findings suggest that readers with ADHD have specific difficulty in retrieving central ideas that are available in their long-term memory. It supports the hypothesis that readers with ADHD establish fewer connections between text ideas during reading, and consequently benefit from a reduced number of retrieval cues after reading.

Multifactorial context effects on visual recognition memory

While effects of contextual change or constancy on memory are widely found when tested by free and cued recall, there is greater inconsistency in context effects on recognition. This study employed a paradigm maximizing target–context interactivity and specificity to reveal three levels of context effects on successful retrieval, as well as context effects on the generation of false alarms, thereby revealing separable contributions of target–context binding, additive familiarity, and configural constancy. The separability of these factors enables the use of memory context effects as tools for investigating associative memory.

Distinct eye movements for different cognitive processes as expressed in the face recognition task

Contemporary research literature indicates that eye movements during the learning and testing phases can predict and affect future recognition processes. Nevertheless, only partial information exists regarding eye movements in the various components of recognition processes: Hits, Correct rejections, Misses and False Alarms (FA). In an attempt to address this issue, participants in this study viewed human faces in a yes/no recognition memory paradigm. They were divided into two groups - one group that carried out the testing phase immediately after the learning phase (n = 30) and another group with a 15-minute delay between phases (n = 28). The results showed that the Immediate group had a lower FA rate than the Delay group, and that no Hit rate differences were observed between the two groups. Eye movements differed between the recognition processes in the learning and the testing phases, and this pattern interacted with the group type. Hence, eye movement measures seem to track memory accuracy during both learning and testing phases and this pattern also interacts with the length of delay between learning and testing. This pattern of results suggests that eye movements are indicative of present and future recognition processes.

Anticipation Measures of Sequence Learning: Manual versus Oculomotor Versions of the Serial Reaction Time Task

The serial reaction time (SRT) task has generated a very large amount of research. Nevertheless the debate continues as to the exact cognitive processes underlying implicit sequence learning. Thus, the first goal of this study is to elucidate the underlying cognitive processes enabling sequence acquisition. We therefore compared reaction time (RT) in sequence learning in a standard manual activated (MA) to that in an ocular activated (OA) version of the task, within a single experimental setting. The second goal is to use eye movement measures to compare anticipation, as an additional indication of sequence learning, between the two versions of the SRT. Performance of the group given the MA version of the task ( n = 29) was compared with that of the group given the OA version ( n = 30). The results showed that although overall, RT was faster for the OA group, the rate of sequence learning was similar to that of the MA group performing the standard version of the SRT. Because the stimulus-response association is automatic and exists prior to training in the OA task, the decreased reaction time in this version of the task reflects a purer measure of the sequence learning that occurs in the SRT task. The results of this study show that eye tracking anticipation can be measured directly and can serve as a direct measure of sequence learning. Finally, using the OA version of the SRT to study sequence learning presents a significant methodological contribution by making sequence learning studies possible among populations that struggle to perform manual responses.

Working memory studies among individuals with intellectual disability: An integrative research review

BACKGROUND

Integrative research review infers generalizations about a substantive subject, summarizes the accumulated knowledge that research has left unresolved and generates a new framework on these issues. Due to methodological issues emerging from working memory (WM) studies in the population with non-specific intellectual disability (NSID) (N=64) between 1990-2014, it is difficult to conclude on WM performance in this population.

AIM

This integrative research review aimed to resolve literature conflicts on WM performance among individuals with NSID and to identify the conditions/moderators that govern their WM performance compared to controls with Typical development.

METHOD/PROCEDURE

We used the six stages of integrative research review: problem formulation, data collection, evaluation, data analysis, results, interpretation and discussion.

OUTCOMES AND RESULTS

The findings indicate two types of moderators that determine WM performance in the population with NSID: Participants' moderators (criteria for matching the ID and TD groups, CA and MA), and task moderators [the three WM components of Baddeley and Hitch's (1974) model and task load]. Only an interaction between the two moderators determines WM performance in this population. The findings indicate a hierarchy (from more to less preserved) in WM performance of individuals with NSID: The visuospatial tasks, then some of the executive functions tasks, and the phonological loop tasks being less preserved. Furthermore, at a low level of control, the performance of participants with NSID was preserved beyond the modality and vice versa.

CONCLUSIONS AND IMPLICATIONS

Modality and MA/intelligence determine WM performance of individuals with ID. Educators should prepare intervention programs take the impact of the two moderators into account.

Perceptual asymmetry during free viewing of words and faces: The effect of context on recognition

There is ample evidence supporting the dissociation between the role of the left and right cerebral hemispheres in processing words and faces, respectively. Nevertheless, research has not yet studied the effect of perceptual asymmetry in memory context effect tasks using words and faces. Thus, the present study researches the advantages of presenting information in the right versus left hemispace and the effect of context on recognition when using faces compared to words presented in the right versus left hemispace. Participants (n=60) were assigned either to the group presented with pairs of words, or with pairs of faces. One stimulus in each pair was designated as the target (i.e., to be remembered) and the other served as context (i.e., to be ignored). Half of the targets were presented in the right hemispace, and half were presented in the left hemispace. As predicted, words were better recognized when presented in the right hemispace, while faces were better remembered when presented in the left hemispace. The most interesting finding is the influence of context on lateralized processing of words and pictures. That is, only when words or faces were presented in the left hemispace did contextual information affect target memory (though it yielded a different pattern of effect). Hence, the findings of the present study may be interpreted either as reflecting attentional bias to the left hemispace or structural differences between the hemispheres. Thus, cognitive processes and the content of the stimuli determine which hemisphere will be involved in processing contextual information.

Eye Movement Patterns Characteristic of Cognitive Style

Various tools have been designed to classify the wholistic/analytic cognitive style, based mostly on behavioral data that reveals little about how these processes function. The main goal of this study is to characterize patterns of eye movements (EM) that are typical of learners with tendencies toward wholistic/analytic styles. Forty students completed the E-CSA-W/A test, while their EM were simultaneously monitored. The results revealed that the overall response time of the wholist group was lower in both tasks. The differences in response time between the groups are interpreted as being influenced by impulsive/reflective styles. While the behavioral data provide us with the end result and quantitative differences between the groups, EM provide us with the qualitative information about the process that led to the response. The study showed that the wholist group is characterized by less fixations and transitions than the analytic group, which is interpreted as reflecting use of whole/partial strategy.

Specific Deficit in Implicit Motor Sequence Learning following Spinal Cord Injury

Background

Physical and psychosocial rehabilitation following spinal cord injury (SCI) leans heavily on learning and practicing new skills. However, despite research relating motor sequence learning to spinal cord activity and clinical observations of impeded skill-learning after SCI, implicit procedural learning following spinal cord damage has not been examined.

Objective

To test the hypothesis that spinal cord injury (SCI) in the absence of concomitant brain injury is associated with a specific implicit motor sequence learning deficit that cannot be explained by depression or impairments in other cognitive measures.

Methods

Ten participants with SCI in T1-T11, unharmed upper limb motor and sensory functioning, and no concomitant brain injury were compared to ten matched control participants on measures derived from the serial reaction time (SRT) task, which was used to assess implicit motor sequence learning. Explicit generation of the SRT sequence, depression, and additional measures of learning, memory, and intelligence were included to explore the source and specificity of potential learning deficits.

Results

There was no between-group difference in baseline reaction time, indicating that potential differences between the learning curves of the two groups could not be attributed to an overall reduction in response speed in the SCI group. Unlike controls, the SCI group showed no decline in reaction time over the first six blocks of the SRT task and no advantage for the initially presented sequence over the novel interference sequence. Meanwhile, no group differences were found in explicit learning, depression, or any additional cognitive measures.

Conclusions

The dissociation between impaired implicit learning and intact declarative memory represents novel empirical evidence of a specific implicit procedural learning deficit following SCI, with broad implications for rehabilitation and adjustment.

Clinical neuropsychology in Israel: history, training, practice and future challenges

OBJECTIVE

This is an invited paper for a special issue on international perspectives on training and practice in clinical neuropsychology. We provide a review of the status of clinical neuropsychology in Israel, including the history of neuropsychological, educational, and accreditation requirements to become a clinical neuropsychologist and to practice clinical neuropsychology.

METHOD

The information is based primarily on the personal knowledge of the authors who have been practicing clinical neuropsychology for over three decades and hold various administrative and academic positions in this field. Second, we conducted three ad hoc surveys among clinical and rehabilitation psychologists; heads of academic programs for rehabilitation and neuropsychology; and heads of accredited service providers. Third, we present a literature review of publications by clinical neuropsychologists in Israel.

RESULTS

Most of the clinical neuropsychologists are graduates of either rehabilitation or clinical training programs. The vast majority of neuropsychologists are affiliated with rehabilitation psychology. The training programs (2-3 years of graduate school) provide solid therapeutic and diagnostic skills to the students. Seventy-five percent of the participants in this survey are employed at least part-time by public or state-funded institutions. Israeli neuropsychologists are heavily involved in case management, including vocational counseling, and rehabilitation psychotherapy. Conclusions and future goals: Although clinical neuropsychologists in Israel are well educated and valued by all health professionals, there are still several challenges that must be addressed in order to further advance the field and the profession. These included the need for Hebrew-language standardized and normalized neuropsychological tests and the application of evidence-based interventions in neuropsychological rehabilitation.

In a context of time: the impact of delay and exposure time on the emergence of memory context effects

Research on context-mediated facilitation of recognition memory distinguishes between the effects of reinstating the exact same context previously associated with a target and a context that is familiar but not directly associated with the target. As both effects are difficult to produce reliably in recognition experiments, attention has turned to measures that may explain inconsistencies, such as the extent to which instructions encourage association between targets and contexts. The aim of the current study was to examine the distinctive and interactive effects of three factors that may lead to variability in context effects (CEs), namely type of instructions given at learning, delay between learning and test, and exposure time for targets and contexts at learning. Using a comprehensive paradigm developed by Vakil and colleagues, with photographs of faces serving as target and context stimuli, both exposure time and delay were shown to be associated with the occurrence of CEs and appeared to interact with one another in determining the nature of these effects. Unlike several previous studies, false alarms did not increase when foils were presented with familiar contexts. Also unexpectedly, the instruction manipulation did not appear to strengthen target-context binding. It may instead have increased attention to contexts at the expense of targets, as suggested by the finding that direct memory for context improved under associative instruction conditions. Overall, the study demonstrates the importance of understanding and controlling various factors that may potentially influence the emergence of both reinstatement and familiarity-based CEs, among them exposure time and learning-to-test delay.

Performance of Children With Developmental Dyslexia on Two Skill Learning Tasks-Serial Reaction Time and Tower of Hanoi Puzzle: A Test of the Specific Procedural Learning Difficulties Theory

Among the various theories proposed to explain developmental dyslexia (DD), the theory of specific procedural learning difficulties has gained certain support and is the framework for the current research. This theory claims that an inability to achieve skill automaticity explains the difficulties experienced by individuals with DD. Previous research on automaticity and DD has exhibited methodological issues such as a failure to test a range of skills. The current study broadens previous findings by delineating various reading skills correlated with several aspects of skill acquisition. Furthermore, the study utilizes two nonverbal tasks that reflect distinct types of skills: Serial Reaction Time (SRT) and the Tower of Hanoi Puzzle (TOHP). A total of 53 children aged 11 to 13 participated in the study, of whom 23 were children with DD and 30 were controls. Participants completed a test battery that consisted of reading tests, the SRT, and the TOHP. Results show no differences in learning rate between individuals with or without DD, although individuals with DD performed both tasks at a slower rate. Correlations were identified between a number of reading measures and measures of skill acquisition, expressed primarily in individuals with DD. Implications are examined in the discussion.

Verbal learning across the lifespan: an analysis of the components of the learning curve

Previous studies on the acquisition process of verbal material, conducted separately on child and adult populations, reveal that the lifespan is characterized by an inverted-U performance curve with similar achievements at its two poles. To clarify the acquisition mechanism across the entire lifespan, the learning curve for the Rey Auditory Verbal Learning Test was reproduced for participants aged 8-91. The study utilized typical trial summary scores and a more refined analysis of trial-by-trial single-word recalls, including omissions (missed words that were previously recalled), additions (recalled words previously missed), and touched words (a count for the first recall time only, for each word during the five learning trial). A clear age effect was shown for the number of words recalled - symmetrically increases during childhood and decreases in adulthood. Similarly, increased turnover of words omitted and added characterized both incremental and decremental age differences. Measurement patterns differed for the age segments on the two sides of the lifespan, despite the similar total number of words recalled by the two sides. Acquisition pattern in children was characterized by a higher number of touched words and higher turnover than for adult groups. In contrast, older adults achieved fewer touched words and lower turnover than the child groups. This study shows that it is possible to reach the same quantitative results via different cognitive processes. The results are interpreted in terms of specific mechanisms of maturational characteristics.

Probabilistic category learning in developmental dyslexia: Evidence from feedback and paired-associate weather prediction tasks

OBJECTIVE

Developmental dyslexia is presumed to arise from specific phonological impairments. However, an emerging theoretical framework suggests that phonological impairments may be symptoms stemming from an underlying dysfunction of procedural learning.

METHOD

We tested procedural learning in adults with dyslexia (n = 15) and matched-controls (n = 15) using 2 versions of the weather prediction task: feedback (FB) and paired-associate (PA). In the FB-based task, participants learned associations between cues and outcomes initially by guessing and subsequently through feedback indicating the correctness of response. In the PA-based learning task, participants viewed the cue and its associated outcome simultaneously without overt response or feedback. In both versions, participants trained across 150 trials. Learning was assessed in a subsequent test without presentation of the outcome, or corrective feedback.

RESULTS

The dyslexia group exhibited impaired learning compared with the control group on both the FB and PA versions of the weather prediction task.

CONCLUSIONS

The results indicate that the ability to learn by feedback is not selectively impaired in dyslexia. Rather it seems that the probabilistic nature of the task, shared by the FB and PA versions of the weather prediction task, hampers learning in those with dyslexia. Results are discussed in light of procedural learning impairments among participants with dyslexia.

Cognitive procedural learning among children and adolescents with or without spastic cerebral palsy: the differential effect of age

INTRODUCTION

Children learn to engage their surroundings skillfully, adopting implicit knowledge of complex regularities and associations. Probabilistic classification learning (PCL) is a type of cognitive procedural learning in which different cues are probabilistically associated with specific outcomes. Little is known about the effects of developmental disorders on cognitive skill acquisition.

METHODS

Twenty-four children and adolescents with cerebral palsy (CP) were compared to 24 typically developing (TD) youth in their ability to learn probabilistic associations. Performance was examined in relation to general cognitive abilities, level of motor impairment and age.

RESULTS

Improvement in PCL was observed for all participants, with no relation to IQ. An age effect was found only among TD children.

CONCLUSIONS

Learning curves of children with CP on a cognitive procedural learning task differ from those of TD peers and do not appear to be age sensitive.

Baseline performance and learning rate of conceptual and perceptual skill-learning tasks: the effect of moderate to severe traumatic brain injury

Existing literature presents a complex and inconsistent picture of the specific deficiencies involved in skill learning following traumatic brain injury (TBI). In an attempt to address this difficulty, individuals with moderate to severe TBI (n = 29) and a control group (n = 29) were tested with two different skill-learning tasks: conceptual (i.e., Tower of Hanoi Puzzle, TOHP) and perceptual (i.e., mirror reading, MR). Based on previous studies of the effect of divided attention on these tasks and findings regarding the effect of TBI on conceptual and perceptual priming tasks, it was predicted that the group with TBI would show impaired baseline performance compared to controls in the TOHP task though their learning rate would be maintained, while both baseline performance and learning rate on the MR task would be maintained. Consistent with our predictions, overall baseline performance of the group with TBI was impaired in the TOHP test, while the learning rate was not. The learning rate on the MR task was preserved but, contrary to our prediction, response time of the group with TBI was slower than that of controls. The pattern of results observed in the present study was interpreted to possibly reflect an impairment of both the frontal lobes as well as that of diffuse axonal injury, which is well documented as being affected by TBI. The former impairment affects baseline performance of the conceptual learning skill, while the latter affects the overall slower performance of the perceptual learning skill.

A deficit in optimizing task solution but robust and well-retained speed and accuracy gains in complex skill acquisition in Parkinson׳s disease: multi-session training on the Tower of Hanoi Puzzle

INTRODUCTION

There are inconsistent results in the research literature relating to whether a procedural memory dysfunction exists as a core deficit in Parkinson׳s disease (PD). To address this issue, we examined the acquisition and long-term retention of a cognitive skill in patients with moderately severe PD. To this end, we used a computerized version of the Tower of Hanoi Puzzle.

METHODS

Sixteen patients with PD (11 males, age 60.9±10.26 years, education 13.8±3.5 years, disease duration 8.6±4.7 years, UPDRS III "On" score 16±5.3) were compared with 20 healthy individuals matched for age, gender, education and MMSE scores. The patients were assessed while taking their anti-Parkinsonian medication. All participants underwent three consecutive practice sessions, 24-48h apart, and a retention-test session six months later. A computerized version of the Tower of Hanoi Puzzle, with four disks, was used for training. Participants completed the task 18 times in each session. Number of moves (Nom) to solution, and time per move (Tpm), were used as measures of acquisition and retention of the learned skill.

RESULTS

Robust learning, a significant reduction in Nom and a concurrent decrease in Tpm, were found across all three training sessions, in both groups. Moreover, both patients and controls showed significant savings for both measures at six months post-training. However, while their Tpm was no slower than that of controls, patients with PD required more Nom (in 3rd and 4th sessions) and tended to stabilize on less-than-optimal solutions.

CONCLUSIONS

The results do not support the notion of a core deficit in gaining speed (fluency) or generating procedural memory in PD. However, PD patients settled on less-than-optimal solutions of the task, i.e., less efficient task solving process. The results are consistent with animal studies of the effects of dopamine depletion on task exploration. Thus, patients with PD may have a problem in exploring for optimal task solution rather than in skill acquisition and retention per se.

Deficit in implicit motor sequence learning among children and adolescents with spastic cerebral palsy

Skill learning (SL) is learning as a result of repeated exposure and practice, which encompasses independent explicit (response to instructions) and implicit (response to hidden regularities) processes. Little is known about the effects of developmental disorders, such as Cerebral Palsy (CP), on the ability to acquire new skills. We compared performance of CP and typically developing (TD) children and adolescents in completing the serial reaction time (SRT) task, which is a motor sequence learning task, and examined the impact of various factors on this performance as indicative of the ability to acquire motor skills. While both groups improved in performance, participants with CP were significantly slower than TD controls and did not learn the implicit sequence. Our results indicate that SL in children and adolescents with CP is qualitatively and quantitatively different than that of their peers. Understanding the unique aspects of SL in children and adolescents with CP might help plan appropriate and efficient interventions.

Premorbid personality characteristics and attachment style moderate the effect of injury severity on occupational outcome in traumatic brain injury: another aspect of reserve

The concept of "reserve" has been proposed to account for the mismatch between brain pathology and its clinical expression. Prior efforts to characterize this concept focused mostly on brain or cognitive reserve measures. The present study was a preliminary attempt to evaluate premorbid personality and emotional aspects as potential moderators in moderate-to-severe traumatic brain injury. Using structural equation modeling and multiple regression analyses, we found that premorbid personality characteristics provided the most robust moderator of injury severity on occupational outcome. Findings offer preliminary support for premorbid personality features as another relevant reserve construct in predicting outcome in this population.

Attentional requirements during acquisition and consolidation of a skill in normal readers and developmental dyslexics

OBJECTIVE

Previous research demonstrated that individuals with developmental dyslexia (DD) may suffer from a deficit in the acquisition stage of a new skill, whereas consolidation processes seem to be preserved. The present study was designed to examine whether this impaired acquisition was attributable to a lack of automatization, and whether the reported preserved consolidation was attributable to the use of DDs' conscious compensation strategies. These aims were implemented by testing a skill-learning task in dyslexics and normal readers using a dual task paradigm. The impact of dual task costs on participants' performance was used as an indication for automaticity.

METHOD

DD and control groups completed a sequence-learning task over a first session (acquisition) and a second session 24 hours later (consolidation). The task was performed by half of the participants under a full attention condition and by the other half under a divided attention condition.

RESULTS

Consistent with previous reports in the literature, divided attention impaired sequence learning in both groups. Nevertheless, divided attention resulted in delayed acquisition of the motor skill in the DD group compared with normal readers. Finally, divided attention enhanced motor procedural consolidation only in the control group.

CONCLUSIONS

The differential effect of divided attention on acquisition and consolidation of procedural skill in DD and normal readers supports the cerebellum deficit hypothesis in DD. In addition, the enhanced skill consolidation in normal readers under divided attention suggests that attentional requirements are not necessary for all types of human learning.

Learning and memory-related brain activity dynamics are altered in systemic lupus erythematosus: a functional magnetic resonance imaging study

Background

Memory impairment is prevalent in systemic lupus erythematosus (SLE); however, the pathogenesis is unknown.

Methods

We studied 12 patients with SLE without clinically overt neuropsychiatric manifestations and 11 matched healthy controls, aiming to characterize neural correlates of memory impairment, using structural and functional magnetic resonance imaging (MRI). The paradigm consisted of three encoding and free-recall cycles, allowing characterization of dynamics along consecutive retrieval attempts.

Results

During learning, patients with SLE and healthy controls showed brain activity changes in two principal networks, the default mode network (DMN) and the task-positive network (TPN). Patients with SLE demonstrated significantly less deactivation in the DMN and greater activation in the TPN, reflecting greater recruitment of both networks. The anterior medial prefrontal cortex (amPFC) of the DMN emerged as the only region where brain activity dynamics were altered both over the learning process ( p < 0.006), and within free-recall period attempts ( p < 0.034). Patients showed significant positive correlations between learning efficiency and hippocampal activity, and greater hippocampal functional connectivity, with pronounced connectivity to DMN structures.

Conclusions

Increased brain activation in patients with SLE during learning may reflect compensatory mechanisms to overcome memory impairment. Our findings localize this impairment to the amPFC, consistent with the behavioral pattern seen in SLE. Altered networking of the hippocampal subsystem of the DMN is consistent with hippocampal neuronal damage seen in SLE, and may reflect compensatory cortical reorganization to cope with dysfunction in these regions pivotal to mnemonic functions.