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Auditory event-related potentials associated with perceptual reversals of bistable pitch motion.

Davidson GD, Pitts MA - Front Hum Neurosci (2014)

Bottom Line: Previous event-related potential (ERP) experiments have consistently identified two components associated with perceptual transitions of bistable visual stimuli, the "reversal negativity" (RN) and the "late positive complex" (LPC).Pairs of complex tones with ambiguous pitch relationships were presented sequentially while subjects reported whether they perceived the tone pairs as ascending or descending in pitch.These two components may be auditory analogs of the visual RN and LPC, suggesting functionally equivalent but anatomically distinct processes in auditory vs. visual bistable perception.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Reed College Portland, OR, USA.

ABSTRACT
Previous event-related potential (ERP) experiments have consistently identified two components associated with perceptual transitions of bistable visual stimuli, the "reversal negativity" (RN) and the "late positive complex" (LPC). The RN (~200 ms post-stimulus, bilateral occipital-parietal distribution) is thought to reflect transitions between neural representations that form the moment-to-moment contents of conscious perception, while the LPC (~400 ms, central-parietal) is considered an index of post-perceptual processing related to accessing and reporting one's percept. To explore the generality of these components across sensory modalities, the present experiment utilized a novel bistable auditory stimulus. Pairs of complex tones with ambiguous pitch relationships were presented sequentially while subjects reported whether they perceived the tone pairs as ascending or descending in pitch. ERPs elicited by the tones were compared according to whether perceived pitch motion changed direction or remained the same across successive trials. An auditory reversal negativity (aRN) component was evident at ~170 ms post-stimulus over bilateral fronto-central scalp locations. An auditory LPC component (aLPC) was evident at subsequent latencies (~350 ms, fronto-central distribution). These two components may be auditory analogs of the visual RN and LPC, suggesting functionally equivalent but anatomically distinct processes in auditory vs. visual bistable perception.

No MeSH data available.


Intermittent stimulus presentation sequence and corresponding example percepts across trials. In this example, the subject reports the perceived pitch direction of the tone pair as ascending in the first trial (white background) and also ascending in the second trial (blue background). Thus the second trial would be categorized as a “stable” trial because perceived pitch direction remained the same across successive trials. The tone pair in the third trial (red background) was perceived as descending and would be categorized as a reversal trial because perceived pitch direction differed from the immediately preceding trial. Each tone was presented for 400 ms in immediate succession, while trials were separated by a silent ISI of variable duration (500–900 ms). Subjects indicated their perceived pitch direction after each tone pair.
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Figure 2: Intermittent stimulus presentation sequence and corresponding example percepts across trials. In this example, the subject reports the perceived pitch direction of the tone pair as ascending in the first trial (white background) and also ascending in the second trial (blue background). Thus the second trial would be categorized as a “stable” trial because perceived pitch direction remained the same across successive trials. The tone pair in the third trial (red background) was perceived as descending and would be categorized as a reversal trial because perceived pitch direction differed from the immediately preceding trial. Each tone was presented for 400 ms in immediate succession, while trials were separated by a silent ISI of variable duration (500–900 ms). Subjects indicated their perceived pitch direction after each tone pair.

Mentions: Trials were presented in blocks of 65, separated by short rest breaks of approximately 15 s. Sets of four blocks were separated by longer 2-min breaks, and each subject completed 12 or 16 blocks for a total of 780 or 1040 total trials. Trials were segregated into conditions by comparing the reported perception on a given trial to the perception on the previous trial. A trial was considered a reversal if reported percepts differed between adjacent trials and stable if perception remained the same. The experiment commenced after 12 blocks (3 sets of 4) if each of these two conditions (reversal and stable) contained at least 150 trials; otherwise an additional set of four blocks was administered. Figure 2 shows a schematic of the stimulus presentation sequence and perceptual reporting task.


Auditory event-related potentials associated with perceptual reversals of bistable pitch motion.

Davidson GD, Pitts MA - Front Hum Neurosci (2014)

Intermittent stimulus presentation sequence and corresponding example percepts across trials. In this example, the subject reports the perceived pitch direction of the tone pair as ascending in the first trial (white background) and also ascending in the second trial (blue background). Thus the second trial would be categorized as a “stable” trial because perceived pitch direction remained the same across successive trials. The tone pair in the third trial (red background) was perceived as descending and would be categorized as a reversal trial because perceived pitch direction differed from the immediately preceding trial. Each tone was presented for 400 ms in immediate succession, while trials were separated by a silent ISI of variable duration (500–900 ms). Subjects indicated their perceived pitch direction after each tone pair.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4126364&req=5

Figure 2: Intermittent stimulus presentation sequence and corresponding example percepts across trials. In this example, the subject reports the perceived pitch direction of the tone pair as ascending in the first trial (white background) and also ascending in the second trial (blue background). Thus the second trial would be categorized as a “stable” trial because perceived pitch direction remained the same across successive trials. The tone pair in the third trial (red background) was perceived as descending and would be categorized as a reversal trial because perceived pitch direction differed from the immediately preceding trial. Each tone was presented for 400 ms in immediate succession, while trials were separated by a silent ISI of variable duration (500–900 ms). Subjects indicated their perceived pitch direction after each tone pair.
Mentions: Trials were presented in blocks of 65, separated by short rest breaks of approximately 15 s. Sets of four blocks were separated by longer 2-min breaks, and each subject completed 12 or 16 blocks for a total of 780 or 1040 total trials. Trials were segregated into conditions by comparing the reported perception on a given trial to the perception on the previous trial. A trial was considered a reversal if reported percepts differed between adjacent trials and stable if perception remained the same. The experiment commenced after 12 blocks (3 sets of 4) if each of these two conditions (reversal and stable) contained at least 150 trials; otherwise an additional set of four blocks was administered. Figure 2 shows a schematic of the stimulus presentation sequence and perceptual reporting task.

Bottom Line: Previous event-related potential (ERP) experiments have consistently identified two components associated with perceptual transitions of bistable visual stimuli, the "reversal negativity" (RN) and the "late positive complex" (LPC).Pairs of complex tones with ambiguous pitch relationships were presented sequentially while subjects reported whether they perceived the tone pairs as ascending or descending in pitch.These two components may be auditory analogs of the visual RN and LPC, suggesting functionally equivalent but anatomically distinct processes in auditory vs. visual bistable perception.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Reed College Portland, OR, USA.

ABSTRACT
Previous event-related potential (ERP) experiments have consistently identified two components associated with perceptual transitions of bistable visual stimuli, the "reversal negativity" (RN) and the "late positive complex" (LPC). The RN (~200 ms post-stimulus, bilateral occipital-parietal distribution) is thought to reflect transitions between neural representations that form the moment-to-moment contents of conscious perception, while the LPC (~400 ms, central-parietal) is considered an index of post-perceptual processing related to accessing and reporting one's percept. To explore the generality of these components across sensory modalities, the present experiment utilized a novel bistable auditory stimulus. Pairs of complex tones with ambiguous pitch relationships were presented sequentially while subjects reported whether they perceived the tone pairs as ascending or descending in pitch. ERPs elicited by the tones were compared according to whether perceived pitch motion changed direction or remained the same across successive trials. An auditory reversal negativity (aRN) component was evident at ~170 ms post-stimulus over bilateral fronto-central scalp locations. An auditory LPC component (aLPC) was evident at subsequent latencies (~350 ms, fronto-central distribution). These two components may be auditory analogs of the visual RN and LPC, suggesting functionally equivalent but anatomically distinct processes in auditory vs. visual bistable perception.

No MeSH data available.