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R Remington

Publications and source records attributed to R Remington.

11 recordsLinked to original sources

Prospective memory in dynamic environments: effects of load, delay, and phonological rehearsal.

A new paradigm was developed to examine prospective memory performance in a visual-spatial task that resembles some aspects of the work of air traffic controllers. Two experiments examined the role of workload (number of aeroplanes that participants directed), delay (between receipt of prospective instructions and execution), and phonological rehearsal. High workload increased prospective memory errors but increasing delay from 1-3 or 5 minutes had no effect. Shadowing aurally presented text reduced prospective memory performance, presumably because it prevented verbal rehearsal of the prospective instructions. However, performance on the foreground task of directing aeroplanes to routine destinations was affected only by workload and not by opportunity for rehearsal. Our results suggest that ability to maintain performance on a routine foreground task while performing a secondary task--perhaps analogous to conversation--does not predict ability to retrieve a prospective intention to deviate from the routine.

Adolescent↗

Can new objects override attentional control settings?

Previous research suggests that attentional capture by abrupt onsets is contingent on top-down attentional control settings. Four experiments addressed whether similar contingencies hold for capture elicited by the appearance of new perceptual objects. In a modified spatial cuing task, targets defined by abrupt onset or color were paired with distractors consisting of an abrupt brightening of an existing object or the abrupt appearance of a new object. In Experiments 1 and 2, when subjects searched for an onset target, both distractor types produced evidence of capture. When subjects searched for a color target, however, distractors produced no evidence of attentional capture, regardless of whether they consisted of a new perceptual object or not. Experiments 3-5 showed that the lack of distractor effects in the color-target condition cannot be accounted for by rapid recovery from capture. It was concluded that attentional capture by new objects is subject to top-down modulation by attentional control settings.

Adolescent↗

Selectivity in distraction by irrelevant featural singletons: evidence for two forms of attentional capture.

Four experiments addressed the degree of top-down control over attentional capture in visual search for featural singletons. In a modified spatial cuing paradigm, the spatial relationship and featural similarity of target and distractor singletons were systematically varied. Contrary to previous studies, all 4 experiments showed that when searching for a singleton target, an irrelevant featural singleton captures spatial attention only when defined by the same feature value as the target. Experiments 2, 3 and 4 provided a potential explanation for the discrepancy with previous studies by showing that irrelevant singletons can produce distraction effects that are dissociable from shifts of spatial attention. The results suggest the existence of 2 distinct forms of attentional capture.

Adolescent↗

A bcl-2 expressing viral vector protects cortical neurons from excitotoxicity even when administered several hours after the toxic insult.

The product of the bcl-2 oncogene has been shown to play an important role in apoptosis and programmed cell death. In this study, a herpes simplex virus type-1 vector was constructed to carry the human bcl-2 gene. The possible role of bcl-2 in protecting neurons from excitoxicity was investigated by using the viral vector to deliver the gene into neuronal cultures before or after the cells were exposed to glutamate under conditions in which 50-80% of neurons died. Infection with the bcl-2 expressing vector 24 h prior to glutamate treatment effectively prevented the cell death that normally follows this treatment. Moreover, infection with the vector as late as 8 h after the glutamate insult still resulted in substantial neuroprotective effects. These results have potential implications for new therapies in stroke or ischemic neuropathies.

Cerebral Cortex↗

The representation of color and form in long-term memory.

Color and form are elementary stimulus encoding dimensions that have effects on the representation of visual stimuli at early processing stages. Little is known, however, about their effects on visual long-term memory. In three experiments we investigated whether color is part of the memory representation, whether color and form are bound in the memory representation, and the effect of color context on memory performance. Experimental results suggest that color is part of the memory representation and that color and form can be represented separately in memory and accessed independently. We suggest that the binding of color and form is a deliberate strategic act that requires focal attention, not a natural consequence of processing visual stimuli. We compare our results with the predictions of two computational memory models regarding feature binding. The effect of color context was not straightforward; however, results are consistent with the encoding specificity principle.

Color Perception↗

Processing of phonemes in speech: a speed-accuracy study.

The present study investigated the serial or parallel processing of phenemes within a syllable. Subjects were required to press a key, on cue, to indicate whether two successive, binaural CVC syllables were the same or different. The cue was a tone which occurred at varying times after the onset of the second CVC and often interrupted its presentation. Subjects' accuracy as a function of time was compared for discriminations involving the first, second, and third phonemes. The results show that information about the phonemes within a CVC syllable is accruing simultaneously. The importance of these results for models of speech perception is discussed.

Auditory Perception↗