Visual Semantic Memory Research Articles

The Semantic Association Test (SAT): normative data from healthy Italian participants and a validation study in aphasic patients.

The Semantic Association Test assesses several aspects of Semantic Memory (Categorical, Encyclopedic, Functional, and Visual Encyclopedic associations: CAs, EAs, FAs and VEAs), using a picture-to-picture matching paradigm. Normative data were collected from a group of 329 healthy participants (178 females) with mean 51.1 (range 20-90) years of age and mean 11.89 (range 5-19) years of education. Raw scores of healthy participants, pre-calculated correction factors for age and educational level, and Equivalent Scores are provided. The SAT was validated in a sample of 139 left brain-damaged persons with aphasia (PWA). Both groups (healthy participants and PWA) scored worse in the CA and EA conditions. The performance of the PWA group was overall defective, and global aphasics scored worse than persons with other types of aphasia. However, several PWA did not show impairments in the SAT. Dissociations were also found, with individual PWA showing defective performance confined to a single category. These results present the SAT as a tool that is useful to detect impairments of visual Semantic Memory, providing normative data from healthy participants and a validation study in PWA.

The persistence of remote visual semantic memory following ocular blindness

Subjects with complete ocular blindness in both eyes provide a unique opportunity to study the long-term durability of visual semantic memory. In this cross-sectional study we recruited eleven subjects who had acquired blindness for between 1 and 36 years. For comparison, we studied four subjects with congenital blindness and seventeen age- and sex-matched sighted control subjects. We administered ten forced-choice questionnaires that probed one auditory category and four visual categories, namely object shape and size; object hue and lightness; word and letter shape; and the shape and features of famous faces. Subjects with congenital blindness performed worse than controls on all visual categories, but nevertheless performed better than chance on object structure or colour, suggesting that the answers to some questions about visual properties can be derived from haptic or non-visual semantic information. Subjects with acquired blindness performed similarly to controls on all categories except for facial memory, particularly for facial features. We conclude that there is a substantial “permastore” of visual semantic memory but that facial memories are less durable, perhaps indicating that they are either less over-learned or more dependent on visual representations than other forms of visual object information.

RO-10PROSPECTIVE SLOPES OVER EIGHT YEARS IN COGNITIVE MARKERS OF PHOTON RADIOTHERAPY FOR PEDIATRIC BRAIN TUMORS

RO-10. PROSPECTIVE SLOPES OVER EIGHT YEARS IN COGNITIVE MARKERS OF PHOTON RADIOTHERAPY FOR PEDIATRIC BRAIN TUMORS Carol L. Armstrong1,2, Julie Petersen1,3, Michael J. Fisher1,2, Robert A. Lustig1,2, Jane E. Minturn1,2, Jean B. Belasco1,2, Sarah Amedoro1, Cathy Bolton3, Peter C. Phillips1,2, and Christine E. Hill-Kayser1,2; The Children’s Hospital of Philadelphia, Philadelphia, PA, USA; The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Drexel University, Philadelphia, PA, USA PURPOSE: This prospective longitudinal study examined late-delayed effects (pre-treatment to 8y) of IMRT/conformal photon radiotherapy (RT) on cognition in children with brain tumors. We previously demonstrated that memory systems are affected differentially by RT, and investigated the pattern over eight years of these RT-specific cognitive markers. At the latedelayed phase, clinical information suggests a generalized decline in cognition, but no prospective studies report the late phase cognitive toxicity (.5 yr post treatment). METHODS: Participants were 28 patients with mixed primary brain tumors (18 males; age range: 4-17, M 1⁄4 9.04, SD 1⁄4 3.32; 61% had grosstotal resection)whocompletedbaseline andat leastone follow-upassessment frombaseline-8years (115 visits). Verbal-semantic memory wasassessed using a supraspan test of word memory (Rey Auditory Verbal Learning (RAVL, 4-forms)) for encoding, retrieval after interference, and retrieval after a delay. Complex Figure (CF, 2-forms) measured visuoperceptual memory immediately and after delay. Picture Recognition (PR) measured visual-semantic memory (accuracy, speed to recognize). Analyses used age-referenced Z scores in a mixed effects model; whole brain versus focal RT was a covariate. RESULTS: Verbal retrieval indices, but not encoding, were sensitive to the late-effects with progressive decline, and greater detriment in hippocampus-sensitive delayed retrieval. CF recall demonstrated continuous improvement to eight years. Bi-hemispherically processed PR demonstrated no decline over eight years. Dose burden significantly predicted retrieval but not encoding or recognition. CONCLUSIONS: Results evidence significant change over time, with differential changes in cognition, and no general decline. The sensitivity of retrieval infers multi-substrate injury not limited to hippocampus. Neuro-Oncology 18:iii159–iii164, 2016. doi:10.1093/neuonc/now082.10 #The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Hopfield neural network model for explaining double dissociation in semantic memory impairment

The purpose of this study was to look for possibility whether Hopfield model can be one of candidates of models for human semantic memory organization. In the field of cognitive psychology, the generalized context model, proposed by Nosofsky, has been considered as a promising one. This model insists that category judgment of human subjects depend upon all memory traces previous experienced. Being analogous Hopfield neural network model with the generalized context model, it is suggested that human semantic memory might be formulated using Hopfield model. It is well-known in neuropsychology that animate and inanimate concepts are separately declined by brain damages. Warrington and her colleagues proposed the hypothesis, that the knowledge about visual and functional features are separately represented in our brains. Animate objects would share more visual properties than inanimate objects. On the other hand, inanimate objects are often defined by their functional features. According to this visual/functional hypothesis, Farah and McClelland (1991) proposed a neural network model to explain the double dissociation. They decided the number and ratio of processing units to deal with functional and visual properties from their psychological experiment. The results succeeded in showing category specificity, when they destroyed the network. However, it can be pointed out that their results was be obvious and no simulations were needed. The reason is that if animate objects/concepts had sent information to visual semantic memory more than those of inanimate objects, then animate specific category disorders must emerge inevitably when semantic memory would suffer damages. There are no needs for discussions nor simulations about this. However, no considerations about the ratio and validity had not been conducted so far. Tyler et al constructed a stimulus set and tried to explain the double dissociation to use this data set. In other words, Farah & McClelland sought the origin of double dissociation from intrinsic semantic memory organization. On the other hand, Tyler sought it from external stimulus structure. However, the reason and/or the degree of contribution of both factors have still remained unsolved. Therefore, mathematical considerations and simulation were conducted. The result showed that the ratio of neuron group, which dealt with, particular information might affect on the performance of the network. This parameter has higher contribution than the external data structure. If so, when brain damages would destroy this area, concept of animate objects might destroy in accordance with the degree of damages. However, we must remember that the validity of Farah and McClelland's ratio must be justified by all possible methodologies. In addition, we might not discard the Tyler structure as the origin of category specificity. It seems to be plausible that Tyler structure might be learned day by day, and then the ratio of Farah and McClelland as semantic memory organization might emerge as human semantic memory representation.

Dyslexia, a deficit or a difference: Comparing the creativity and memory skills of dyslexic and nondyslexic students in Iran

Positive and negative aspects of dyslexia were explored within the Iranian context. Dyslexia can be considered either as a deficit or merely as a difference. In this study 26 dyslexic primary-school students in Tehran were matched with 26 nondyslexics. The Shirazi and Nilipur (2004) Diagnostic Reading Test was administered to identify any significant difference in reading ability between the two groups. Then the Torrance (1974; as cited in Alizadeh, 1994) Creativity Test (Form B, picture subtest) and the Cornoldi (1995; as cited in Kakavand, 2003) Test of Visual-Spatial and Verbal Memory were used. Nondyslexics outperformed dyslexics significantly in visual-verbal memory of words for concrete objects and abstract concepts and in audio-verbal memory of words for abstract concepts. Dyslexic students performed significantly better in visual and audio memory of concrete words compared to abstract concepts; their visual-spatial memory was better than their visual-semantic memory, and their pictorial memory was also better than their verbal memory. Dyslexic students scored higher than nondyslexics for original thinking and equally as high in overall creativity. These findings indicate that a change of attitude is needed toward dyslexics.

How central is central coherence?

This study aimed to test the assumption drawn from weak central coherence theory that a central cognitive mechanism is responsible for integrating information at both conceptual and perceptual levels. A visual semantic memory task and a face recognition task measuring use of holistic information were administered to 15 children with autism and 16 typically developing children. If there is a central integration mechanism, performance on the two tasks should be positively associated. No relationship was found, however, between the two abilities in the comparison group and, unexpectedly, a strong significant inverse correlation was found in the autism group. Classification data further confirmed this finding and indicated the possibility of the presence of subgroups in autism. The results add to emerging evidence suggesting that central coherence is not a unitary construct.