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Trials effects in single-trial ERP components and autonomic responses at very long ISIs

Journal Article


Abstract


  • Early studies examining the Orienting Reflex (OR) utilised single-trial

    autonomic measures at long ISIs, permitting full resolution of responses.

    To investigate central correlates for the OR, ERP studies have often

    employed positional averaging of ERP responses across blocks to improve

    the signal/noise ratios. However, this maymask the rapid initial response

    characteristic of the OR. More recent ERP research employed shorter ISIs,

    often under a fewseconds. Paradigms incorporating long ISIs canproduce

    robust single-trial ERP waveforms, yielding central data concurrently

    with autonomic measures. Undergraduates (10 females and 6 males of

    mean age 24.2 years), as part of fulfilling course requirements,

    participated in a simple auditory dishabituation paradigm.We compared

    response patterns of single-trial ERPs, HR, and respiratory responses to

    the phasic skin conductance response (SCR) commonly used as the

    Orienting Reflex (OR) benchmark. Twelve 80 dB tones (1000/1500 Hz,

    50 ms with 15 ms rise/fall times)were presented with randomISIs (45 to

    70 s), with no task requirements. The first 10 standard trials were of one

    frequency, followed by a change trial at the other frequency (recovery),

    and subsequent dishabituation trial at the initial standard frequency. The

    evoked cardiac response (ECR), Respiratory Pause (RP), SCR, and singletrial

    ERPs from 19 sites, were collected. EOG-corrected ERP data were

    submitted to principal components analysis (PCA). SCR displayed

    decrement over trials, response recovery at the change trial, and

    dishabituation at the following standard. ECR showed no trial effects.

    RP decreased linearly over trials and displayed amarginal recovery at the

    change trial. Eight identifiable ERP components were extracted: P1, N1,

    Processing Negativity, P2, P3a, P3b, Novelty P3 and the SlowWave (SW);

    only SWshowed significant decrement over trials, but without recovery

    or dishabituation. Only the SCR fulfilled the formal definition of

    habituation required of the OR. The early phasic cardiac response,

    observed as a deceleration unaffected by trials, can be linked to processing

    of the stimulus onset transient. The respiratory pause decrement over

    trials suggests processing marking the novelty aspect of the stimulus,

    subsequent to that reflected in the cardiac response, but prior to the OR.

    Of the ERP PCA components, only the SW demonstrated an overall

    diminished response over trials, but without recovery or dishabituation,

    aligning it with processing prior to the OR. This study supports

    predictions of Preliminary Processing Theory demonstrating the fractionation

    of 3 autonomic and 8 ERP componentswith respect to the novelty

    determinant of the OR, and disconfirming the unitary nature of the OR.

Publication Date


  • 2012

Citation


  • MacDonald, B. & Barry, R. J. (2012). Trials effects in single-trial ERP components and autonomic responses at very long ISIs. International Journal of Psychophysiology, 85 (3), 314-315.

Ro Metadata Url


  • http://ro.uow.edu.au/hbspapers/3107

Number Of Pages


  • 1

Start Page


  • 314

End Page


  • 315

Volume


  • 85

Issue


  • 3

Abstract


  • Early studies examining the Orienting Reflex (OR) utilised single-trial

    autonomic measures at long ISIs, permitting full resolution of responses.

    To investigate central correlates for the OR, ERP studies have often

    employed positional averaging of ERP responses across blocks to improve

    the signal/noise ratios. However, this maymask the rapid initial response

    characteristic of the OR. More recent ERP research employed shorter ISIs,

    often under a fewseconds. Paradigms incorporating long ISIs canproduce

    robust single-trial ERP waveforms, yielding central data concurrently

    with autonomic measures. Undergraduates (10 females and 6 males of

    mean age 24.2 years), as part of fulfilling course requirements,

    participated in a simple auditory dishabituation paradigm.We compared

    response patterns of single-trial ERPs, HR, and respiratory responses to

    the phasic skin conductance response (SCR) commonly used as the

    Orienting Reflex (OR) benchmark. Twelve 80 dB tones (1000/1500 Hz,

    50 ms with 15 ms rise/fall times)were presented with randomISIs (45 to

    70 s), with no task requirements. The first 10 standard trials were of one

    frequency, followed by a change trial at the other frequency (recovery),

    and subsequent dishabituation trial at the initial standard frequency. The

    evoked cardiac response (ECR), Respiratory Pause (RP), SCR, and singletrial

    ERPs from 19 sites, were collected. EOG-corrected ERP data were

    submitted to principal components analysis (PCA). SCR displayed

    decrement over trials, response recovery at the change trial, and

    dishabituation at the following standard. ECR showed no trial effects.

    RP decreased linearly over trials and displayed amarginal recovery at the

    change trial. Eight identifiable ERP components were extracted: P1, N1,

    Processing Negativity, P2, P3a, P3b, Novelty P3 and the SlowWave (SW);

    only SWshowed significant decrement over trials, but without recovery

    or dishabituation. Only the SCR fulfilled the formal definition of

    habituation required of the OR. The early phasic cardiac response,

    observed as a deceleration unaffected by trials, can be linked to processing

    of the stimulus onset transient. The respiratory pause decrement over

    trials suggests processing marking the novelty aspect of the stimulus,

    subsequent to that reflected in the cardiac response, but prior to the OR.

    Of the ERP PCA components, only the SW demonstrated an overall

    diminished response over trials, but without recovery or dishabituation,

    aligning it with processing prior to the OR. This study supports

    predictions of Preliminary Processing Theory demonstrating the fractionation

    of 3 autonomic and 8 ERP componentswith respect to the novelty

    determinant of the OR, and disconfirming the unitary nature of the OR.

Publication Date


  • 2012

Citation


  • MacDonald, B. & Barry, R. J. (2012). Trials effects in single-trial ERP components and autonomic responses at very long ISIs. International Journal of Psychophysiology, 85 (3), 314-315.

Ro Metadata Url


  • http://ro.uow.edu.au/hbspapers/3107

Number Of Pages


  • 1

Start Page


  • 314

End Page


  • 315

Volume


  • 85

Issue


  • 3