Electrophysiological responses to images ranging in motivational salience: Attentional abnormalities associated with schizophrenia-spectrum disorder risk

Abstract

Individuals at risk for schizophrenia-spectrum disorders display abnormalities related to motivational salience, or the ability of stimuli to elicit attention due to associations with rewards or punishments. However, the nature of these abnormalities is unclear because most focus on responses to stimuli from broad "pleasant" and "unpleasant" categories and ignore the variation of motivational salience within these categories. In two groups at risk for schizophrenia-spectrum disorders-a Social Anhedonia group and a Psychotic-like Experiences group-and a control group, the current study examined event-related potential components sensitive to motivational salience-the Early Posterior Negativity (EPN), reflecting earlier selective attention, and the Late Positive Potential (LPP), reflecting sustained attention. Compared to controls, the Social Anhedonia group showed smaller increases in the EPN in response to erotica and smaller increases in the LPP as the motivational salience of pleasant images increased (exciting<affiliative<erotica). In contrast, the Psychotic-like Experiences group had larger increases in LPP amplitudes as the motivational salience of pleasant images increased. Also, both at-risk groups showed larger increases in the LPP to threatening images but smaller increases to mutilation images. These findings suggest that examining abnormalities beyond those associated with broad categories may be a way to identify mechanisms of dysfunction.

Figure 1

Stimulus-locked ERPs averaged at POz, Oz, O1, and O2 (EPN) for each of the pleasant subcategories (exciting, affiliative, erotic) by group. The gray bar indicates the portion of the waveform used in analysis.

Figure 2

Stimulus-locked ERPs averaged at Pz, P3, P4, CPz, CP1, and CP2 (LPP) for each of the pleasant subcategories (exciting, affiliative, erotic) by group. The gray bar indicates the portion of the waveform used in analysis. (Note: Based on the dependability analyses, more participants were excluded from the Late LPP analyses due to an insufficient number of trials retained. Thus, there are separate figures for the Early and the Late LPP.).

Figure 3

Stimulus-locked ERPs averaged at Pz, P3, P4, CPz, CP1, and CP2 (LPP) for each of the unpleasant subcategories (disgusting, threatening, mutilation) by group. The gray bar indicates the portion of the waveform used in analysis. (Note: Based on the dependability analyses, more participants were excluded from the Late LPP analyses due to an insufficient number of trials retained. Thus, there are separate figures for the Early and the Late LPP.).

Figure 4

Stimulus-locked ERPs averaged at Pz, P3, P4, CPz, CP1, and CP2 (LPP) for each of the neutral subcategories (objects, scenes without people, scenes with people) by group. The gray bar indicates the portion of the waveform used in analysis. (Note: Based on the dependability analyses, more participants were excluded from the Late LPP analyses due to an insufficient number of trials retained. Thus, there are separate figures for the Early and the Late LPP.).