ABSTRACT The mismatch negativity (MMN) is an event‐related brain potential elicited by infrequent, physically deviant sounds in a sequence of repetitive auditory stimuli. Two dichotic listening experiments that were designed to optimize the selective focusing attention provided strong test Näätänen's proposal MMN unaffected and reflects operation strongly automatic detection system. In Experiment 1, tones presented at intervals 120‐320 ms, (intensity decrements) both attended unattended ears...

A series of studies assessed perceptual-motor transmission stimulus information by measuring lateralization movement-related brain potentials in a choice reaction task with no-go trials. When stimuli varied shape and size, lateralized on trials suggested that easily recognized was used to initiate motor preparation this aborted when size analysis signified the response should be withheld. This indicates movement can begin once partial perceptual about becomes available, contrary an...

ABSTRACT Short latency evoked potentials were recorded during a cross‐modal selective attention task to evaluate recent proposals that sensory transmission in the peripheral auditory and visual pathways can be modified selectively by centrifugal mechanisms humans. Twenty young adult subjects attended turn either left‐ear tones or right‐field flashes presented randomized sequence, order detect infrequent, lower‐intensity targets. Attention‐related enhancement of longer‐latency components,...

Given that Parkinson's disease broadly affects frontostriatal circuitry, it is not surprising the disorder associated with a reduction of working memory. We tested whether this due to diminished storage capacity or impaired ability exclude task-irrelevant items. Twenty-one medication-withdrawn patients and 28 age-matched control subjects performed visuospatial memory task while their electroencephalograms were recorded. The required them remember orientations red rectangles within half...

Recently, electromyographic (EMG) signals of auricular muscles have been shown to be an indicator spatial auditory attention in humans, based on a vestigial pinna-orienting system. Because competing speaker task is closely related the more generalized concept attentional effort listening, current study investigated possibility that EMG activity could also reflect correlates effortful listening general. Twenty participants were recruited. from left and right superior posterior (SAM, PAM)...

ABSTRACT Two versions of a selective listening experiment were conducted in an attempt to specify the level nervous system at which attention first influences auditory information processing. Post‐auricular reflexes (PARs), preputse inhibition reflexes, and N1 component event‐related potential (ERP) measured concurrently assess processing hindbrain. midbrain. forebrain. respectively. Sequences intense, reflex‐eliciting tones presented two ears random order rapid rate as subjects listened...

The question of whether automatic, sensory processes can be modified by selectively directing attention to stimuli was addressed comparing effects on brainstem reflexes that share a common efferent pathway but have distinct afferent limbs. Subjects judged the duration brief intense blink-eliciting tones (Experiment 1) or weak preceding air puff at interstimulus intervals producing blink inhibition 2). Tones occurred unpredictably left, right, midline loci; designation target location varied...

Abstract Fundamental properties of an important new tool in cognitive electrophysiology, the lateralized readiness potential (LRP), were examined two experiments. Experiment 1 resolved apparent inconsistency literature by demonstrating that this response‐specific lateralization is larger preceding complex then simple finger movements. In 2, foveally presented precue, which indicated hand response, preceded go/no‐go stimulus 0, 100, 300, or 1,400 ms. Analyses LRP latency hand‐specific...

Abstract When an intense but task-irrelevant “accessory” stimulus accompanies the imperative in a choice reaction task, times (RTs) are facilitated. In similar previous study (Hackley & Valle-Inclán, 1998), we showed that this effect is not due to reduction of interval from onset lateralized readiness potential (LRP) until movement onset. present study, RT task was modified move portion response selection stage into time interval. The remained invariant, indicating late phase process...

Abstract Previous research using nonchronometric measures in humans and animals has shown that warning signals can influence stages of processing throughout the reaction time (RT) interval. However, latency indicate effects on RT are not due to speeding motor processes, at least late ones. To better isolate chronometric temporal preparation, we used lateralized event‐related potentials divide mean into three segments. Foreperiod duration had only a small, nonsignificant first last segments...

Abstract Sixteen neurologically normal volunteers performed a 2‐choice speeded reaction time (RT) task in which the imperative was change color of clock hand. During trial blocks with low temporal uncertainty (good condition), this stimulus occurred at fixed location (e.g., 2:00). In bad condition, unpredictive onset. On half both good and trials, task‐irrelevant, cutaneous accessory accompanied imperative. The speeding reactions by associated activation primarily near supramarginal gyrus...

ABSTRACT Prior work, has shown that reflex blinking can be facilitated by directing attention to the stimulus. It was assumed if facilitation were due sensory enhancement, would also novelty‐induced orienting prior reflex‐eliciting The assumption tested establishing an expectancy for weak tactile stimulation followed acoustic stimulus and then introducing, without announcement, trials on which or visual stimuli occurred Interspersed control of alone provided baseline data. Novel did produce...

We investigated the relationship between action-outcome contingency and stimulus-preceding negativity (SPN), a motivationally sensitive event-related potential. Neuroimaging studies have shown that insular cortex (a known source of SPN) is more activated prior to rewards are contingent on correct action than given gratuitously. compared two gambling tasks, one in which participant attempted guess profitable key-press option (choice) were simply at random (no-choice). The SPN developed...