Robert Till

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Peripheral processes in vision were investigated in two experiments involving monoptic backward masking with random noise. For young and old subjects, peripheral processing time (represented by stimulus onset asynchrony of target and mask) was characterized as a power function of target energy. Although processing time for both age groups showed a similar(More)
Peripheral processing, as defined by Turvey (1973), was investigated in a study of binocular backward masking involving random visual noise. For young (mean age 20.3 years) and old (mean age 55.4 years) adults, processing time (represented by stimulus onset asynchrony, SOA) was characterized as a power function of target energy (TE) (i.e., TEb x SOA = K).(More)
In two experiments, subjects recalled one of two letter sequences following a digit-filled retention interval. Recall performance was increased by precues informing subjects which letter sequence would be tested, and the cuing advantage remained throughout 60-digit retention intervals. No improvement was found, however, for cues occurring after the letters(More)
Bdellovibrio bacteriovorus is a Delta-proteobacterium that oscillates between free-living growth and predation on Gram-negative bacteria including important pathogens of man, animals and plants. After entering the prey periplasm, killing the prey and replicating inside the prey bdelloplast, several motile B. bacteriovorus progeny cells emerge. The B.(More)
In a study of recognition memory for pictures, we observed an asymmetry in classifying test items as "same" versus "different" in left-right orientation: Identical copies of previously viewed items were classified more accurately than left-right reversals of those items. Response bias could not explain this asymmetry, and, moreover, correct "same" and(More)
Age differences in visual information processing were investigated in a study of monoptic backward masking. Young (18 to 22) and old (58 to 73) adults were tested in three experiments utilizing both a random visual noise and a pattern (fragments) mask, with two-letter combinations serving as target stimuli. Critical target duration needed to escape masking(More)
One specific analog of arginine vasopressin, 1-desamine-8-D-arginine vasopressin (DDAVP), has been shown to improve learning and memory in humans. Healthy young male adult subjects treated with DDAVP demonstrated better memory for implicational sentences than did control subjects. The same treatment had no influence on women given the same memory task.(More)
In two experiments, subjects recalled one of two letter segments following a digit-filled retention interval. In Experiment 1, recall expectancy was manipulated by using precues that correctly informed or misinformed subjects concerning which letter segment would be tested for recall. In Experiment 2, item importance was varied by precuing one segment as(More)
Previous research on recognition memory has examined age-related effects on knowledge of the difference between lures and input items (e.g., false alarm rate), but has not examined age-related effects on knowledge of the resemblance between lures and input items. In the present experiment, subjects in two age groups (means = 19.3 years and 63.8 years) saw a(More)
Although several studies have demonstrated the efficacy of the vasopressin analog DDAVP in enhancing human memory, no previous study has reported the dose-response relationship of DDAVP to memory in healthy young adults. The present study was undertaken to explore the dose-response curve for DDAVP on recall of implicational sentences. Five doses of DDAVP(More)