Standard diagnostic procedures for assessing temporal-processing abilities of adult patients with aphasia have so far not been developed. In our study, temporal-order measurements were conducted using two different experimental procedures to identify a suitable measure for clinical studies. Additionally, phoneme-discrimination abilities were tested on the word, as well as on the sentence level,...

The relative power of the hippocampal theta-band ( approximately 6 Hz) activity (theta ratio) is thought to reflect a distinct neural state and has been shown to affect learning rate in classical eyeblink conditioning in rabbits. We sought to determine if the theta ratio is mostly related to the detection of the contingency between the stimuli used in conditioning or also to the learning of mor...

We examined whether observers veridically perceive the reflectances of real objects under natural viewing conditions. A new forced-choice paradigm was used to measure observers' abilities to identify (not match) the reflectance of randomly crumpled gray papers across two levels of illumination, and also to simultaneously measure brightness discrimination thresholds for the same objects. Accurac...

Two experiments explored the behavior of 20 Asian elephants (Elephas aximus) in simultaneous visual discrimination tasks. In Experiment 1, 7 Burmese logging elephants acquired a white+/black- discrimination, reaching criterion in a mean of 2.6 sessions and 117 discrete trials, whereas 4 elephants acquired a black+/white- discrimination in 5.3 sessions and 293 trials. One elephant failed to reac...

PURPOSE The claim that speech perception abilities are impaired in dyslexia was investigated in a group of 62 children with dyslexia and 51 average readers matched in age. METHOD To test whether there was robust evidence of speech perception deficits in children with dyslexia, speech perception in noise and quiet was measured using 8 different tasks involving the identification and discrimina...

Brightness discrimination thresholds and facilitation by lateral interaction were measured in five human observers and two monkeys. The subjects judged the brightness of one of four peripherally seen lines against a reference. This experiment was performed both when the observer was cued to the position of the test line (focused attention) and when there was no cue (distributed attention). Disc...

The purpose of this study was to analyze fear extinction and reinstatement in humans using fear-potentiated startle. Participants were fear conditioned using a simple discrimination procedure with colored lights as the conditioned stimuli (CSs) and an airblast to the throat as the unconditioned stimulus (US). Participants were extinguished 24 h after fear conditioning. Upon presentation of unsi...

Perceptual learning may occur when multiple contrasts are practiced in a fixed, but not in a roving (random), temporal sequence. However, learning may escape roving disruption when each contrast is assigned a letter tag (i.e., A, B, C, D). Because these letter tags carry not only stimulus identity information, but also semantic sequence information, here we investigated whether the semantic seq...

Sound localization in humans depends largely on interaural time delay (ITD). The ability to discriminate differences in ITD is highly accurate. ITD discrimination (Delta ITD) thresholds, under some circumstances, are as low as 10-20 micros. It has been assumed that thresholds this low could only be obtained if the outputs from many neurons were combined. Here we use Receiver Operating Character...

The present study aimed to investigate neurophysiological substrates of phoneme and word processing in 10 patients with acute aphasia (PWA). More specifically, phoneme discrimination was studied in a passive and active oddball task with respect to different phonemic contrasts, while lexical detection was investigated by presenting infrequent pseudowords among frequent words in a passive oddball...