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M Mouloua

Publications and source records attributed to M Mouloua.

4 recordsLinked to original sources
PubMed1994

Effects of spatial cuing on luminance detectability: psychophysical and electrophysiological evidence for early selection.

Three experiments were conducted to determine whether attention-related changes in luminance detectability reflect a modulation of early sensory processing. Experiments 1 and 2 used peripheral cues to direct attention and found substantial effects of cue validity on target detectability; these effects were consistent with a sensory-level locus of selection but not with certain memory- or decision-level mechanisms. In Experiment 3, event-related brain potentials were recorded in a similar paradigm using central cues, and attention was found to produce changes in sensory-evoked brain activity beginning within the 1st 100 ms of stimulus processing. These changes included both an enhancement of sensory responses to attended stimuli and a suppression of sensory responses to unattended stimuli; the enhancement and suppression effects were isolated to different neural responses, indicating that they may arise from independent attentional mechanisms.

Adolescent↗
PubMed1990

Visual attention modulates signal detectability.

The mechanism by which visual-spatial attention affects the detection of faint signals has been the subject of considerable debate. It is well known that spatial cuing speeds signal detection. This may imply that attentional cuing modulates the processing of sensory information during detection or, alternatively, that cuing acts to create decision bias favoring input at the cued location. These possibilities were evaluated in 3 spatial cuing experiments. Peripheral cues were used in Experiment 1 and central cues were used in Experiments 2 and 3. Cuing similarly enhanced measured sensitivity, P(A) and d', for simple luminance detection in all 3 experiments. Under some conditions it also induced shifts in decision criteria (beta). These findings indicate that visual-spatial attention facilitates the processing of sensory input during detection either by increasing sensory gain for inputs at cued locations or by prioritizing the processing of cued inputs.

Adult↗
PubMedDate not supplied

Aging and cognitive vigilance: effects of spatial uncertainty and event rate.

Age-related differences in cognitive vigilance were examined in a task requiring identification of a target (a lowercase letter) presented at three levels of spatial uncertainty (low, moderate, and high) and in the context of a low or high event rate. Thirty-six young (18-24 years) and 36 older (60-74 years) adults participated in 30-min vigilance sessions. Increased spatial uncertainty decreased target detection rate and d' to a greater extent in older adults than in young adults. No age differences were obtained for the low-spatial-uncertainty condition. The vigilance decrement--the decline in detection rate over time--was magnified when event rate was high and when spatial uncertainty was high. The results suggest that cognitive vigilance is age sensitive when demands on visual attention capacity are increased by high event rate or spatial uncertainty.

Adolescent↗