This chapter contains sections titled: The Problem, The Generalized Delta Rule, Simulation Results, Some Further Generalizations, Conclusion

/pdf/learning-internal-representations-by-error-propagation-100fypr7vm.pdf

Learning internal representations by error propagation

Thank you for downloading using multivariate statistics. As you may know, people have look hundreds times for their favorite novels like this using multivariate statistics, but end up in infectious downloads. Rather than reading a good book with a cup of tea in the afternoon, instead they juggled with some harmful bugs inside their laptop. using multivariate statistics is available in our digital library an online access to it is set as public so you can download it instantly. Our books collection saves in multiple locations, allowing you to get the most less latency time to download any of our books like this one. Merely said, the using multivariate statistics is universally compatible with any devices to read.

Using Multivariate Statistics

The unity and diversity of executive functions and their contributions to complex "Frontal Lobe" tasks: a latent variable analysis.

We review evidence for partially segregated networks of brain areas that carry out different attentional functions. One system, which includes parts of the intraparietal cortex and superior frontal cortex, is involved in preparing and applying goal-directed (top-down) selection for stimuli and responses. This system is also modulated by the detection of stimuli. The other system, which includes the temporoparietal cortex and inferior frontal cortex, and is largely lateralized to the right hemisphere, is not involved in top-down selection. Instead, this system is specialized for the detection of behaviourally relevant stimuli, particularly when they are salient or unexpected. This ventral frontoparietal network works as a 'circuit breaker' for the dorsal system, directing attention to salient events. Both attentional systems interact during normal vision, and both are disrupted in unilateral spatial neglect.

Control of goal-directed and stimulus-driven attention in the brain

▪ Abstract The prefrontal cortex has long been suspected to play an important role in cognitive control, in the ability to orchestrate thought and action in accordance with internal goals. Its neural basis, however, has remained a mystery. Here, we propose that cognitive control stems from the active maintenance of patterns of activity in the prefrontal cortex that represent goals and the means to achieve them. They provide bias signals to other brain structures whose net effect is to guide the flow of activity along neural pathways that establish the proper mappings between inputs, internal states, and outputs needed to perform a given task. We review neurophysiological, neurobiological, neuroimaging, and computational studies that support this theory and discuss its implications as well as further issues to be addressed

/pdf/an-integrative-theory-of-prefrontal-cortex-function-2j9unprn5f.pdf

An integrative theory of prefrontal cortex function

Psychology and social control.

We studied the ability of patients with lesions arising from operation for an anterior or posterior (left or right) brain tumour to read a set of words and pronounceable nonwords. In line with previous works, we observed that damage to the left posterior or left anterior cortex can give rise to phonological alexia, where the reading performance of nonwords is affected more than that of words. More surprisingly, similar effects were found in the right posterior group. However, there were significant differences in the error types, for both complex and positional errors, between phonological alexic patients in the three location groups. The findings present difficulties for the position held by theorists of the triangle model that phonological alexia arises from impairments in the language production system or in a general-purpose orthographic-phonological translation system. They also pose new questions about the possible role of the right posterior cortex in letter sequence representation.

Left- and right-hemisphere forms of phonological alexia.

Objective: Existing studies on memory interference in Parkinson's disease (PD) patients have provided mixed results and it is unknown whether PD patients have problems in overcoming interference from retrieval cues. We investigated this issue by using a part-list cuing paradigm. In this paradigm, after the study of a list of items, the presentation of some of these items as retrieval cues hinders the recall of the remaining ones. Method: We tested PD patients' (n = 19) and control participants' (n = 16) episodic memory in the presence and absence of part-list cues, using initial-letter probes, and following either weak or strong serial associative encoding of list items. Results: Both PD patients and control participants showed a comparable and significant part-list cuing effect after weak associative encoding (13% vs. 12% decrease in retrieval in part-list cuing vs. no part-list cuing -control- conditions in PD patients and control participants, respectively), denoting a similar effect of cue-driven interference in the two populations when a serial retrieval strategy is hard to develop. However, only PD patients showed a significant part-list cuing effect after strong associative encoding (20% vs. 5% decrease in retrieval in patients and controls, respectively). Conclusions: When encoding promotes the development of an effective serial retrieval strategy, the presentation of part-list cues has a specifically disruptive effect in PD patients. This indicates problems in strategic retrieval, probably related to PD patients' increased tendency to rely on external cues. Findings in control conditions suggest that less effective encoding may have contributed to PD patients' memory performance.

Interference from retrieval cues in Parkinson's disease

The left frontal lobe is critical for the AH4 fluid intelligence test

This chapter argues that single case studies of memory, or investigations in which a small number of very similar patients are studied, have been highly influential in shaping the history of ideas on memory. Memory is a field where most of the greatest scientific advances from neuropsychological investigations have come from studies of a single patient, or less frequently, a few very similar patients, each treated as individuals. The seemingly more standard method of contrasting the average performance of large groups of patients has made much less of a splash. Descriptions of individual patients with selective disorders were a standard procedure in the late 19th century until the 1920s, and this was to become neuropsychological research. The approach reached its acme in the work of the diagram makers in language towards the end of the 19th century. This link between cognitive psychology and neuropsychology led to experimental memory paradigms developed by cognitive psychologists being applied to the study of patients.

Tim Shallice

Papers

Psychology and social control.

Left- and right-hemisphere forms of phonological alexia.

Interference from retrieval cues in Parkinson's disease

The left frontal lobe is critical for the AH4 fluid intelligence test

The Single Case Study of Memory