Components of high-level vision: a cognitive neuroscience analysis and accounts of neurological syndromes

Coach Encouragement During Soccer Practices Can Influence Players' Mental and Physical Loads

This study analyzed the influence of the coaches' encouragement on the mental and physical load in soccer practices. The participants were 36 semiprofessional Spanish soccer players (Mage = 22.40; SD = 2.25) belonging to two male teams and one female team. Following the same practices' design and order, two training sessions of each team were completed. In one session, coaches maintained a passive verbal attitude, whereas in the other session, coaches intervened with an active attitude through continuous general encouragement. The mental load and fatigue were measured using self-reported questionnaires (Likert scales), and internal and external physical loads were quantified using the rating of perceived exertion and the Global Position System. A t-test for related samples and magnitude based on an inference spreadsheet was performed. The results demonstrated that mental and internal physical loads increased when coaches participated with active verbal encouragement. Especially, increases in performance satisfaction, mental effort, and RPE values, and decreases in unsafety values were detected due to encouragement interventions. Nevertheless, the external physical load did not show a clear trend. Based on these findings, coaches can use this information to manipulate their verbal encouragement during practices according to their physical and mental objectives with specific soccer strategies.

The elements of executive attention in top soccer referees and assistant referees

The aim of the present study was to compare executive attention of top soccer referees and assistant referees at different levels of professional attainment. The sample consisted of 53 subjects (FIFA and national level) - 30 referees and 23 assistant referees. Executive attention of assistant referees was significantly better than the referees' (p<0.01). Furthermore, extraclass and international referees demonstrated better executive attention than the first-league referees (p<0.01). The research results have proved that referees' executive attention differs depending on their function and professional level, as well as indicated that the quality of abilities may influence the number and correctness of decisions made during a game. This elementary cognitive process may be strongly shaped by individual's experience and age. This finding may be instrumental in screening referees and developing criteria for recruiting future referees.

Priming and multiple memory systems: perceptual mechanisms of implicit memory

Abstract Research examining the relation between explicit and implicit forms of memory has generated a great deal of evidence concerning the issue of multiple memory systems. This article focuses on an extensively studied implicit memory phenomenon, known as direct or repetition priming, and examines the hypothesis that priming effects on various tasks reflect the operation of a perceptual representation system (PRS)-a class of cortically based subsystems that operate at a presemantic level and support non conscious expressions of memory. Three PRS subsystems are examined: visual word form, structural description, and auditory word form. Pertinent cognitive, neuropsychological, and neurobiological evidence is reviewed, alternative classificatory schemes are discussed, and important conceptual and terminological issues are considered.

Array Effects, Spatial Concepts, or Information Processing Speed

A reaction time/accuracy experiment investigated the development of visual memory for object shape and location in 6–7- and 8–9-year-old children and adults (N = 72) in three array types: (1) an empty screen, (2) a frame delineating a region, and (3) a grid with individually delineated places. A maximized learning design was used. Explicit array boundaries in the frame and in the grid facilitated place memory in both children and adults, while place memory in the empty screen was less correct, slower, and did not improve. Children’s visual memory was initially low, but learning during the task resulted in better object than place memory. Like the children at the end of the session, adults showed better object than place memory at the beginning of the task. They subsequently also improved their object memory, but doubled their place memory performance. Children with object-region binding showed better place memory and more systematic learning effects that were specific to arrays. However, neither array boundaries nor spatial binding concepts explained the absence of place learning in children. Instead, children tried to prevent proactive shape interference in the repeated memory sets at the cost of place learning, while adults did not.

Visual cognition

Visual cognition, high-level vision, mid-level vision and top-down processing all refer to decision-based scene analyses that combine prior knowledge with retinal input to generate representations. The label "visual cognition" is little used at present, but research and experiments on mid- and high-level, inference-based vision have flourished, becoming in the 21st century a significant, if often understated part, of current vision research. How does visual cognition work? What are its moving parts? This paper reviews the origins and architecture of visual cognition and briefly describes some work in the areas of routines, attention, surfaces, objects, and events (motion, causality, and agency). Most vision scientists avoid being too explicit when presenting concepts about visual cognition, having learned that explicit models invite easy criticism. What we see in the literature is ample evidence for visual cognition, but few or only cautious attempts to detail how it might work. This is the great unfinished business of vision research: at some point we will be done with characterizing how the visual system measures the world and we will have to return to the question of how vision constructs models of objects, surfaces, scenes, and events.

Hemisphere Specialisation and Categorical Spatial Relations Representations

Hemisphere specialisation in two- and three-dimensional categorical spatial relations tasks was investigated using normal adult subjects. In Experiment 1, subjects were asked to indicate the rightmost (or leftmost) card in stimuli consisting of three overlapping cards as quickly and as accurately as possible. The results showed no significant visual field difference in either response times or error rates. In Experiment 2, stimuli identical to those of Experiment 1 were used and subjects were asked to indicate the card most to the front or the one most to the back. The error rates showed a strong tendency towards a left visual field advantage in accuracy while no visual field difference was shown in response times. Based on these findings, relations between the hemisphere specialisation and categorical spatial relations encoding subsystems in Kosslyn's (1987) model of visual information processing are discussed.

Effects of Shape, Size, and Chromaticity of Stimuli on Estimated Size in Normally Sighted, Severely Myopic, and Visually Impaired Students

Effects of shape, size, and chromaticity of stimuli on participants' errors when estimating the size of simultaneously presented standard and comparison stimuli were examined. 48 Taiwanese college students ages 20 to 24 years old ( M = 22.3, SD = 1.3) participated. Analysis showed that the error for estimated size was significantly greater for those in the low-vision group than for those in the normal-vision and severe-myopia groups. The errors were significantly greater with green and blue stimuli than with red stimuli. Circular stimuli produced smaller mean errors than did square stimuli. The actual size of the standard stimulus significantly affected the error for estimated size. Errors for estimations using smaller sizes were significantly higher than when the sizes were larger. Implications of the results for graphics-based interface design, particularly when taking account of visually impaired users, are discussed.

On giving a more active and selective role to consciousness

An active role for conscious processes in the production of behaviour is proposed, involving top level controls in a hierarchy of behavioural control. It is suggested that by inhibiting or sensitizing lower levels in the hierarchy conscious processes can play a role in the organization of ongoing behaviour. Conscious control can be more or less evident, according to prevailing circumstances.

The control of consciousness via a neuropsychological feedback loop

Gray's neuropsychological model of consciousness uses a hierarchical feedback loop framework that has been extensively discussed by many others in psychology. This commentary therefore urges Gray to integrate with, or at least acknowledge previous models. It also points out flaws in his feedback model and suggests directions for further theoretical work.

“What” and “where” in spatial language and spatial cognition

Fundamental to spatial knowledge in all species are the representations underlying object recognition, object search, and navigation through space. But what sets humans apart from other species is our ability to express spatial experience through language. This target article explores the language ofobjectsandplaces, asking what geometric properties are preserved in the representations underlying object nouns and spatial prepositions in English. Evidence from these two aspects of language suggests there are significant differences in the geometric richness with which objects and places are encoded. When an object is named (i.e., with count nouns), detailed geometric properties – principally the object's shape (axes, solid and hollow volumes, surfaces, and parts) – are represented. In contrast, when an object plays the role of either “figure” (located object) or “ground” (reference object) in a locational expression, only very coarse geometric object properties are represented, primarily the main axes. In addition, the spatial functions encoded by spatial prepositions tend to be nonmetric and relatively coarse, for example, “containment,” “contact,” “relative distance,” and “relative direction.” These properties are representative of other languages as well. The striking differences in the way language encodes objects versus places lead us to suggest two explanations: First, there is a tendency for languages to level out geometric detail from both object and place representations. Second, a nonlinguistic disparity between the representations of “what” and “where” underlies how language represents objects and places. The language of objects and places converges with and enriches our understanding of corresponding spatial representations.

Don't leave the “un” off “consciousness”

Gray extrapolates from circuit models of psychopathology to propose neural substrates for the contents of consciousness. I raise three concerns: (1) knowledge of synaptic arrangements may be inadequate to fully support his model; (2) latent inhibition deficits in schizophrenia, a focus of this and related models, are complex and deserve replication; and (3) this conjecture omits discussion of the neuropsychological basis for the contents of the unconscious.

Consciousness is for other people

Gray has expanded his account of schizophrenia to explain consciousness as well. His theory explains neither phenomenon adequately because he treats individual minds (and brains) in isolation. The primary function of consciousness is to permit high level interactions with other conscious beings. The key symptoms of schizophrenia reflect a failure of this mechanism.

Temporal representation in the control of movement

Theories of the representation of specific kinetic and spatiotem-poral features of movement range from the explicit assertion that temporal aspects of movement are not represented (Kugler et al. 1980) to the idea that they are represented and that they have neurophysiological correlates (Ivry & Corcos 1993; Ivry & Keele 1989). Jeannerod's thesis is that mental and visual images have common mechanisms and that there is a link between the image to move and the mechanisms involved with movement. The target article takes the position that certain parameters are coded in motor representations (sect. 4) but that the duration of an action is not one of them. This position is based on the work of Gottlieb et al. (1989b) and of Decety et al. (1989). Both these studies are worth considering in detail. In Note 1, Jeannerod suggests that: “in time-constrained tasks subjects control the amplitude parameter of force impulses, whereas in spatially constrained tasks the duration of the force impulse is affected by accuracy demands.” This is not exactly correct. Excitation pulse intensity (amplitude) is modulated both in tasks that require spatial and those that require temporal accuracy. Excitation pulse duration is modulated for changes in movement distance and inertial load. If subjects are required to be very accurate spatially, they will move at less than maximum speed for a given distance and this is achieved by lower levels of excitation intensity (Gottlieb et al. 1990).

Comparators, functions, and experiences

The comparator model is insufficient for three reasons. First, consciousness is involved in the process of comparison as well as in the output. Second, we still do not have enough neurophysiological information to match the events of consciousness, although such knowledge is growing. Third, the anatomical localisation proposed can be damaged bilaterally but consciousness will persist.

Possible roles for a predictor plus comparator mechanism in human episodic recognition memory and imitative learning

This commentary is divided into two parts. The first considers a possible role for Gray's predictor plus comparator mechanism in human episodic recognition memory. It draws on the computational specifications of recognition outlined in Humphreys et al. (1994) to demonstrate how the logically necessary components of recognition tasks might be mapped onto the mechanism. The second part demonstrates how the mechanism outlined by Gray might be implicated in a form of imitative learning suitable for the acquisition of complex tasks.

Consciousness does not seem to be linked to a single neural mechanism

On the basis of neuropsychological evidence, it is clear that attention should be given a role in any model (or conjecture) of consciousness. What is known about the many instances of dissociation between explicit and implicit knowledge after brain damage suggests that conscious experience might not be linked to a restricted area of the brain. Even if it were true that there is a single brain area devoted to consciousness, the subicular area would seem to be an unlikely possibility.

Segmentalized consciousness in schizophrenia

Segmentalized consciousness in schizophrenia reflects a loss of the normal Gestalt organization and contextualization of perception. Grays model explains such segmentalization in terms of septohippocampal dysfunction, which is consistent with known neuropsychological impairment in schizophrenia. However, other considerations suggest that everyday perception and its failure in schizophrenia also involve prefrontal executive mechanisms, which are only minimally elaborated by Gray.

Neuropsychological inference with an interactive brain: A critique of the “locality” assumption

When cognitive neuropsychologists make inferences about the functional architecture of the normal mind from selective cognitive impairments they generally assume that the effects of brain damage are local, that is, that the nondamaged components of the architecture continue to function as they did before the damage. This assumption follows from the view that the components of the functional architecture are modular, in the sense of being informationally encapsulated. In this target article it is argued that this “locality” assumption is probably not correct in general. Inferences about the functional architecture can nevertheless be made from neuropsychological data with an alternative set of assumptions, according to which human information processing is graded, distributed, and interactive. These claims are supported by three examples of neuropsychological dissociations and a comparison of the inferences obtained from these impairments with and without the locality assumption. The three dissociations are: selective impairments in knowledge of living things, disengagment of visual attention, and overt face recognition. In all three cases, the neuropsychological phenomena lead to more plausible inferences about the normal functional architecture when the locality assumption is abandoned. Also discussed are the relations between the locality assumption in neuropsychology and broader issues, including Fodor's modularity hypothesis and the choice between top-down and bottom-up research approaches.

Unitary consciousness requires distributed comparators and global mappings

Gray, like other recent authors, seeks a scientific approach to consciousness, but fails to provide a biologically convincing description, partly because he implicitly bases his model on a computationalist foundation that embeds the contents of thought in irreducible symbolic representations. When patterns of neural activity instantiating conscious thought are shorn of homuncular observers, it appears most likely that these patterns and the circuitry that compares them with memories and plans should be found distributed over large regions of neocortex.

On seeking the mythical fountain of consciousness

Because consciousness has an organizational, or functional, center, Gray supposes that there must be a corresponding physical center in the brain. He proposes further that since this center generates consciousness, ablating it would eliminate consciousness, while leaving behavior intact. But the center of consciousness is simply the product of the functional linkages among sensory input, memory, inner speech, and so on, and behavior.

Prospects for a cognitive neuroscience of consciousness

In this commentary, I point out some weaknesses in Gray's target article and, in the light of that discussion, I attempt to delineate the kinds of problem a cognitive neuroscience of consciousness faces on its way to a scientific understanding of subjective experience.

Septohippocampal comparator: Consciousness generator or attention feedback loop?

As Gray insists, his comparator model proposes a brute correlation only – of consciousness with septohippocampal output. I suggest that the comparator straddles a feedback loop that boosts the activation ofnovelrepresentations, thus helping them feature in present or recollected experience. Such a role in organizing conscious contents would transcend correlation and help explain how consciousness emerges from brain function.

On the relation between motor imagery and visual imagery

Jeannerod's target article describes support, through empirical and neurological findings, for the intriguing idea of motor imagery, a form of representation hypothesized to have levels of functional equivalence with motor preparation, while being consciously accessible. Jeannerod suggests that the subjectively accessible content of motor imagery allows it to be distinguished from motor preparation, which is unconscious. Motor imagery is distinguished from visual imagery in terms of content. Motor images are kinesthetic in nature; they are parametrized by variables such as force and time and they are potentially governed by kinematic rules. Jeannerod acknowledges, however, that motor and visual imagery may not easily be separated, because actions take place in a spatial environment. I agree; in fact, I suggest here that visualization may generally be concomitant with, and may even subjectively dominate, motor imagery.

The representing brain: Neural correlates of motor intention and imagery

This paper concerns how motor actions are neurally represented and coded. Action planning and motor preparation can be studied using a specific type of representational activity, motor imagery. A close functional equivalence between motor imagery and motor preparation is suggested by the positive effects of imagining movements on motor learning, the similarity between the neural structures involved, and the similar physiological correlates observed in both imaging and preparing. The content of motor representations can be inferred from motor images at a macroscopic level, based on global aspects of the action (the duration and amount of effort involved) and the motor rules and constraints which predict the spatial path and kinematics of movements. A more microscopic neural account calls for a representation of object-oriented action. Object attributes are processed in different neural pathways depending on the kind of task the subject is performing. During object-oriented action, a pragmatic representation is activated in which object affordances are transformed into specific motor schemas (independently of other tasks such as object recognition). Animal as well as human clinical data implicate the posterior parietal and premotor cortical areas in schema instantiation. A mechanism is proposed that is able to encode the desired goal of the action and is applicable to different levels of representational organization.

Perspective, reflection, transparent explanation, and other minds

Perspective and reflection (whether involving conceptual or nonconceptual content) have each been considered in some way basic to phenomenal consciousness. Each has possible evolutionary value, though neither seems sufficient for consciousness. Consider an account of consciousness in terms of the combination of perspective and reflection, its relationship to the problem of other minds, and its capacity to inherit evolutionary explanation from its components.

Psychopathology and the discontinuity of conscious experience

It is accepted that “primary awareness” may emerge from the integration of two classes of information. It is unclear, however, why this cannot take place within the comparator rather than in conjunction with feedback to the perceptual systems. The model has plausibility in relation to the continuity of conscious experience in the normal waking state and may be extended to encompass certain aspects of the “sense of self” which are frequently disrupted in psychotic patients.

Consciousness, memory, and the hippocampal system: What kind of connections can we make?

Gray's account is remarkable in its depth and scope but too little attention is paid to poor correspondences with the literature on hippocampal/subicular damage, the theta rhythm, and novelty detection. An alternative account, focusing on hippocampal involvement in organizing memories in a way that makes them accessible to conscious recollection but not in access to consciousness per se, avoids each of these limitations.