512 research outputs found
Structured representations in the control of behavior cannot be so easily dismissed: a reply to Botvinick and Plaut (2006)
No full textM. Botvinick and D. C. Plaut (2006) argued that many of the criticisms of their earlier simple recurrent network (SRN) model of routine sequential action raised by R. P. Cooper and T. Shallice (2006) were criticisms of the specific implementation rather than criticisms of the underlying theory. Cooper and Shallice (2006) reject this assessment and raise concerns with several implementational adjustments that Botvinick and Plaut made to address their criticisms of the SRN account. Moreover, Botvinick and Plaut are questioned for not addressing potential interactions between their suggested implementational changes. Cooper and Shallice also reconsider the implications of the role of the training set in shaping the SRN model’s normal and error-prone behavior, the role of goals in their original interactive activation network model and routine behavior more generally, and the relation between the putative routine and nonroutine action control systems within the 2 models
Temporal summation and absolute brightness thresholds
No full textThree normative models based on the Change Detector analogies of Shallice (1964) are investigated to see how well they account for the integration of input over time that occurs in absolute brightness threshold experiments. Of the three, the geometric moving average receives no support. The perceptual moment and moving average models give about equally satisfactory but not perfect fits for short flash results, but the perceptual moment model is much more satisfactory for long flash results. The analysis takes into account variations in information transmission times, noise in the visual system and the quantal nature of the light input. The locus of temporal integration is discussed and a central locus preferred, following Treisman (1966)
Fractionation of memory in medial temporal lobe amnesia.
No full textWe report a comprehensive investigation of the anterograde memory functions of two patients with memory impairments (RH and JC). RH had neuroradiological evidence of apparently selective right-sided hippocampal damage and an intact cognitive profile apart from selective memory impairments. JC, had neuroradiological evidence of bilateral hippocampal damage following anoxia due to cardiac arrest. He had anomic and "executive" difficulties in addition to a global amnesia, suggesting atrophy extending beyond hippocampal regions. Their performance is compared with that of a previously reported hippocampal amnesic patient who showed preserved recollection and familiarity for faces in the context of severe verbal and topographical memory impairment [VC; Cipolotti, L., Bird, C., Good, T., Macmanus, D., Rudge, P., & Shallice, T. (2006). Recollection and familiarity in dense hippocampal amnesia: A case study. Neuropsychologia, 44, 489-506.] The patients were administered experimental tests using verbal (words) and two types of non-verbal materials (faces and buildings). Receiver operating characteristic analyses were used to estimate the contribution of recollection and familiarity to recognition performance on the experimental tests. RH had preserved verbal recognition memory. Interestingly, her face recognition memory was also spared, whilst topographical recognition memory was impaired. JC was impaired for all types of verbal and non-verbal materials. In both patients, deficits in recollection were invariably associated with deficits in familiarity. JC's data demonstrate the need for a comprehensive cognitive investigation in patients with apparently selective hippocampal damage following anoxia. The data from RH suggest that the right hippocampus is necessary for recollection and familiarity for topographical materials, whilst the left hippocampus is sufficient to underpin these processes for at least some types of verbal materials. Face recognition memory may be adequately subserved by areas outside of the hippocampus
Effects of Word Abstractness in a Connectionist Model of Deep Dyslexia
No full textness in a Connectionist Model of Deep Dyslexia David C. Plaut School of Computer Science Carnegie Mellon University Pittsburgh, PA 15213 [email protected] Tim Shallice Department of Psychology University College London, England WC1E 6BT [email protected] Proceedings of the 13th Annual Meeting of the Cognitive Science Society, Chicago, IL, August 1991, pages 73--78. Abstract Deep dyslexics are patients with neurologicaldamage who exhibit a variety of symptoms in oral reading, including semantic, visual and morphological effects in their errors, a part-of-speech effect, and better performance on concrete than abstract words. Extending work by Hinton & Shallice (1991), we develop a recurrent connectionist network that pronounces both concrete and abstract words via their semantics, defined so that abstract words have fewer semantic features. The behavior of this network under a variety of "lesions" reproduces the main effects of abstractness on deep dyslexic reading: better correct perfor..
Hierarchical schemas and goals in the control of sequential behavior
No full textTraditional accounts of sequential behavior assume that schemas and goals play a causal role in the control of behavior. In contrast, M. Botvinick and D. C. Plaut (2004) argued that, at least in routine behavior, schemas and goals are epiphenomenal. The authors evaluate the Botvinick and Plaut account by contrasting the simple recurrent network model of Botvinick and Plaut with their own more traditional hierarchically structured interactive activation model (R. P. Cooper & T. Shallice, 2000). The authors present a range of arguments and additional simulations that demonstrate theoretical and empirical difficulties for both Botvinick and Plaut’s model and their theoretical position. The authors conclude that explicit hierarchically organized and causally efficacious schema and goal representations are required to provide an adequate account of the flexibility of sequential behavior
Dorsolateral prefrontal cortex and motor preparation: a TMS investigation of the foreperiod effect
No full textWhen Foreperiods (FPs) of different duration alternate on a trial-by-trial basis equiprobably but randomly, the reaction time (RT) decreases as the FP increases (FP effect). Another phenomenon observed in that paradigm consists of the sequential effects: RT is slower as the FP in the preceding trial gets longer. It is not clear if the two effects are due to different underlying mechanisms. Patients with lesions on the right dorsolateral prefrontal cortex do not show the typical FP effect [Stuss et al. (2005). Neuropsychologia, 43, 396-417]. Aim of the present study was to replicate this result in healthy adults, through an off-line TMS paradigm (Theta Burst Stimulation). Another purpose was to investigate whether any change of the sequential effects would follow a possible variation of the FP effect. Results of two experiments (with simple and choice RT task, respectively) indicate a significant reduction of the FP effect, selectively after stimulation of the right dorsolateral prefrontal cortex with respect to a pre-TMS baseline, and to the stimulation of a contralateral site and of another site in the right Angular Girus. The dissociation between the two effects supports a dual-process model [Vallesi & Shallice, subm.], according to which they are due to two distinct but interacting processes. In particular, the FP effect is attributed to a strategic process monitoring the conditional probability of the stimulus occurrence, whereas the sequential effects would originate by an automatic mechanism of arousal regulation by the length of the preceding FP
Fractionation of the Supervisory System
No full textForeword ; Preface ; 1. Introduction ; 2. The Human Frontal Lobes: Transcending the Default Mode through Contigent Encoding ; 3. Association Pathways of the Prefrontal Cortex and Functional Observations ; 4. Neurochemical Modulation of Prefrontal Cortical Functions in Humans and Animals ; 5. Functional Architecture of the Dorsolateral Prefrontal Cortex in Monkeys and Man ; 6. Physiology of Executive Functions: The Perception-Action Cycle ; 7. The Theatre of the Mind: Physiological Studies of the Human Frontal Lobes ; 8. Motor Programming for Hand and Vocalizing Movements ; 9. Cortical Control of Visuometer Reflexes ; 10. Disorders of Language After Frontal Lobe Injury ; 11. The Organization of Working Memory Function in Lateral Prefrontal Cortex ; 12. The Frontal Cortex and Working with Memory ; 13. Memory Retrieval and Executive Control Processes ; 14. Dorsal Prefrontal Cortex: Maintenance in Memory or Attentional Selection ; 15. Mechanisms of Conflict Resolution in Prefrontal Cortex ; 16. Fractionating the Central Executive ; 17. Fractionation of the Supervisory System ; 18. Cognitive Focus through Adaptive Neural Coding in Primate Prefrontal Cortex ; 19. The Structured Event Complex and the Human Prefrontal Cortex ; 20. Chronesthesia: Conscious Awareness of Subjective Time ; 21. Integration Across Multiple Cognitive and Motivational Domains in Monkey Prefrontal Cortex ; 22. Emotion, Decision-Making and the Ventromedial Prefrontal Cortex ; 23. The Functions of the Orbitofrontal Cortex ; 24. Mapping Mood: An Evolving Emphasis on Frontal-Limbic Interactions ; 25. Fractionation and Localization of Distinct Frontal Lobe Processes: Evidence from Focal Lesions in Humans ; 26. Neurobehavioural Consequences of Neurosurgical Treatments and Focal Lesions of Frontal-Subcortical Circuits ; 27. The Role of Prefrontal Cortex in Normal and Disordered Cognitive Control: A Cognitive Neuroscience Perspective ; 28. Novel Approaches to The Assessment of Frontal Damage and Executive Deficits in Traumatic Brain Injury ; 29. Normal Development of Prefrontal Cortex, from Birth to Young Adulthood: Cognitive Functions, Anatomy and Biochemistry ; 30. Executive Functions Following Frontal Lobe Injury: A Developmental Perspective ; 31. Aging, Memory, and Frontal Lobe Functioning ; 32. Frontal Lobe Plasticity and Behaviour ; 33. Principles of the Rehabilitation of Frontal Lobe Function ; 34. Prefrontal Cortex: The Present and the Futur
The functional imaging of recall
No full textAn associative theory of implicit and explicit memory, G.H. Bower; encoding and retrieval processes - similarities and differences, F.I.M. Craik, M. Naveh-Benjamin, N.D. Anderson; memory imagery - a visual trace is not a mental image, C. Cornoldi, R. de Beni, F. Giusberti, M. Massironi; imaginary memories, E.F. Loftus; the rise and fall of semantic memory, J.M. Mandler; stories, selves and schemata - a review of ecological findings, U. Neisser; associative processes in false recall and false recognition, H.L. Roediger III, K.B. McDermott, K.J. Robinson; the functional imaging of recall, T. Shallice, P. Fletcher, R. Dolan; three dimensions of spatial cognition, B. Tversky. Part contents.
Deconstructing ‘retrieval mode’
No full textM. Naveh-Benjamin, M. Moscovitch, H.L. Roediger, III, Prologue/Preface. Part I: Levels of Processing and Memory Theory. M.J. Watkins, Introduction. E. Tulving, Does Memory Encoding Exist? H.L. Roediger, III, D.A. Gallo, Levels of Processing: Some Unanswered Questions. B.M. Velichkovsky, Levels of Processing: Validating the Concept J.M. Gardiner, A. Richardson-Klavehn, C. Ramponi, B.M Brooks, Involuntary Levels of Processing Effects in Perceptual and Conceptual Priming. B.A. Levy, Fluent Text Processing: Using Memory Representations to Explore Reading Skills. R.S. Lockhart, Discussion. Part II: Working Memory and Attention. M.T. Turvey, Introduction. Working Memory. A.D. Baddeley, Levels of Working Memory. T. Shallice, Deconstructing "Retrieval Mode". Working Memory and Aging. J.M. McDowd, Levels of Processing in Selective Attention and Inhibition: Age Differences and Similarities. D.C. Park, T. Hedden, Working Memory and Aging. M. Daneman, Discussion. Attention at Encoding and Retrieval. M. Moscovitch, Divided Attention, Memory and Neuropsychology. M. Naveh-Benjamin, The Effects of Divided Attention on Encoding Processes: Underlying Mechanisms. N.D. Anderson, The Attentional Demands and Attentional Control of Encoding and Retrieval. C.M. MacLeod, Discussion. Part III: Aging. A.S. Benjamin, Introduction. Age-related Changes in Memory. L.L. Jacoby, E.L. Marsh, P.O. Dolan, Forms of Bias: Age Related Differences in Memory. L-G. Nilsson, Aging, Cognition, and Health. E.L. Glisky, Source Memory, Aging, and the Frontal Lobes. Age-related Changes in Perception and Cognition. T.A. Salthouse, The Broader Context of Craik's Self Initiated Processing Hypothesis. L. Hasher, S.T. Tonev, C. Lustig, Inhibitory Control, Environmental Support, and Self-initiated Processing in Aging. B.A. Schneider, Sensation, Cognition, and Levels of Processing in Aging. L.L. Light, Discussion. Part IV: Neuroscience Perspectives: Memory and Aging. Memory and Aging. A. Randal McIntosh, Introduction. C.L. Grady, Age-related Changes in the Functional Neuroanatomy of Memory. D.T. Stuss, M.A. Binns, Aging: Lot an Escarpment, but Multiple Slopes. P. Vidailhet, B.K. Chrisensen, J.M Danion, S. Kapur, Episodic Memory Impairment in Schizophrenia: A View from Cognitive Psychopathology. W. Koutstaal, D.L. Schacter, Memory Distortion and Aging. G. Winocur, Discussion
Category-specificity and feature knowledge: evidence from new sensory quality categories
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