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

The lexical decision performance of a letter-by-letter reader, ML, was analysed for words presented for too short an exposure duration for him to identify or name them. His level of performance was surprisingly good by comparison with that of previously reported patients. In addition he gave a very similar pattern of responses to inappropriately affixed words as to appropriately affixed ones. His performance on these tasks could not be attributed to neglect or to the use of letter sequential dependencies. In addition, with the same exposure duration, ML showed “semantic access” characteristics in word categorisation tasks. This evidence for lexical processing in the absence of explicit identification is discussed in relation to alternative accounts of letter-by-letter reading.

Lexical processing in the absence of explicit word identification: Evidence from a letter-by-letter Reader

An effect of spatial-temporal association of response codes: understanding the cognitive representations of time.

Introduction Since the 1940s many theorists have suggested that information might be stored in the cognitive system in a different way over short time periods than for longer time periods. A number of possible mechanisms have been proposed – special or general-purpose buffers, the continuing but temporary activation of the structures that have just processed an input, and the formation of temporary associations or temporary changes in association strength. Theoretical arguments for such mechanisms have been produced from a range of scientific fields from physiological psychology (e.g., Hebb, 1949), information-processing psychology (Broadbent, 1958), and symbol-processing artificial intelligence (Newell & Simon, 1972) through to connectionist neuroscience (e.g., Crick, 1984; Hinton & Plaut, 1987). Empirical support has come from a narrower set of approaches. Most of the relevant findings have come from experimental psychology (e.g., Waugh & Norman, 1965; Atkinson & Shiffrin, 1968; Glanzer, 1972; Baddeley & Hitch, 1974), but these have been subject to many criticisms (see, e.g., Craik & Lockhart, 1972; Crowder, 1982). From a neuropsychological perspective, if a short-term memory trace were being carried by certain of the aforementioned mechanisms, a selective deficit to that mechanism would be realized in a selective impairment in behaviour. This is clearly true for the most favoured possibility – damage to a specific short-term memory buffer - given that the buffer was not involved in all cognitive operations. It would also apply for a specific impairment of one of two association-weight-changing mechanisms. For instance, Hinton and Plaut (1987) have simulated a connectionist network using two types of weights – “slow” weights (which change slowly and carry the long-term learning) and “fast” weights (which change rapidly but decay fairly quickly to zero).

Neuropsychological impairments of short-term memory: The impairment of auditory–verbal short-term storage

A very pure and most unusual case of memory impairment is reported in a patient operated on for an aneurysm of the anterior communicating artery. Neuropsychological investigation performed about 8 yrs after the operation revealed a dissociation between very poor performance on recognition tests(on which the patient' performance was as poor as that in classical amnesic patients)and normal performance(estimated by the number of correct responses) in recall. This pattern has not previously been reported and is the reverse of that observed both in normal subjects and in amnesic patients. In addition, the patient was able to achieve a number of difficult learning tasks, at times normally; the relearning of one of these tasks after a delay of I h was perfectly normal. The recognition failure is interpreted in terms of the suggestion that memory performance results from an interaction between knowledge and subjective experience of remembering.

Preserved recall versus impaired recognition:a case study

https://pure.mpg.de/pubman/item/item_2614842_3/component/file_2623363/RD_Sculpting_2000.pdf

Tim Shallice

Papers

Lexical processing in the absence of explicit word identification: Evidence from a letter-by-letter Reader

An effect of spatial-temporal association of response codes: understanding the cognitive representations of time.

Neuropsychological impairments of short-term memory: The impairment of auditory–verbal short-term storage

Preserved recall versus impaired recognition:a case study

"Sculpting the response space"--an account of left prefrontal activation at encoding