Impact of motivational salience on affect modulated startle at early and late probe times.

This study systematically manipulated both picture content and noise probe time in order to evaluate the effects of motivational salience (as distinguished from affective valence) on both early and late modulation of the startle response. Specifically, modulation was compared for erotic versus action/adventure scenes, and for direct threat versus victim scenes, at early (300 and 800 ms) and late (3500 ms) probe times -- all relative to neutral. Blink inhibition was observed at all probe times during presentation of erotic pictures, and blink potentiation was evident at all times during presentation of direct threat pictures. Patterns of blink modulation were less consistent for action and victim picture contents. These findings are consistent with the hypothesis that under conditions of high motivational salience, affective startle modulation indexes the activation of appetitive-approach and defensive motivational states, even at early stages of picture processing.     

Impact of motivational salience on affect modulated startle at early and late probe times

This study systematically manipulated both picture content and noise probe time in order to evaluate the effects of motivational salience (as distinguished from affective valence) on both early and late modulation of the startle response. Specifically, modulation was compared for erotic versus action/adventure scenes, and for direct threat versus victim scenes, at early (300 and 800 ms) and late (3500 ms) probe times — all relative to neutral. Blink inhibition was observed at all probe times during presentation of erotic pictures, and blink potentiation was evident at all times during presentation of direct threat pictures. Patterns of blink modulation were less consistent for action and victim picture contents. These findings are consistent with the hypothesis that under conditions of high motivational salience, affective startle modulation indexes the activation of appetitive-approach and defensive motivational states, even at early stages of picture processing.     

The interaction of anticipatory anxiety and emotional picture processing: An event‐related brain potential study

The present study examined the interaction of anticipatory anxiety and selective emotion processing. Toward this end, a rapid stream of pleasant, neutral, and unpleasant pictures was presented in alternating blocks of threat‐of‐shock or safety, which were signaled by colored picture frames. The main finding is that pleasant pictures elicited a sustained negative difference potential over occipital regions during threat as compared to safety periods. In contrast, unpleasant and neutral picture processing did not vary as a function of threat‐of‐shock. Furthermore, in both the safety and threat‐of‐shock conditions, emotional pictures elicited an enlarged early posterior negativity and late positive potential. These data show that the activation of the fear/anxiety network exerts valence‐specific effects on affective picture processing. Pleasant stimuli mismatching the current state of anticipatory anxiety apparently draw more attentional resources.     

Low baseline startle and deficient affective startle modulation in remitted bipolar disorder patients and their unaffected siblings

We examined whether startle abnormalities are present in bipolar disorder (BD) patients and their unaffected siblings. Twenty‐one remitted patients with BD, 19 unaffected siblings, and 42 controls were presented with 18 pleasant, 18 unpleasant, and 18 neutral pictures. Acoustic probes (104 dB) were presented during 12 of 18 pictures in each affective category at 300, 3000, and 4500 ms after picture onset, so that there were 4 pictures per valence per probe onset type. Baseline startle was assessed during blank screens and was found reduced in patients and sibling groups. We found startle inhibition with the 300 probes and a linear increase in amplitude with valence with the late probes in controls; these effects were absent in patients and their siblings. Low startle and blunted startle reactivity may represent trait deficits in remitted BD patients and their relatives, possibly associated with attentional deficits and adaptive down‐regulation of emotion.     

Modulation of spinal reflexes: Arousal, pleasure, action

The human startle reflex is reliably modulated by the affective valence of foreground pictures, with larger reflexes elicited when viewing unpleasant relative to pleasant scenes. If this modulation is due to priming of the defensive startle reflex by an aversive foreground, a different pattern should occur for a reflex that is not inherently defensive in nature. In the current study, affective modulation was investigated using the spinal tendinous (T) reflex, which is well documented as sensitive to differences in arousal and is involved in actions that are both appetitively and defensively motivated. As such, T reflexes elicited during unpleasant pictures were not expected to be augmented relative to those elicited in the context of pleasant pictures. Results showed that T reflexes were facilitated during processing of arousing stimuli – either pleasant or unpleasant relative to low-arousal neutral materials. These effects of emotional stimuli on T-reflex amplitude are consistent with the hypothesis that motivational priming underlies affective reflex modulation.     

Cognitive reappraisal during unpleasant picture processing: Subjective self‐report and peripheral physiology

Increased attention among the research community in exploring underlying mechanisms of emotion regulation has prompted a growth of experimental works in this field. Empirical studies have mainly focused on self‐reports, brain imaging, and electrophysiological measures, with only a few works exploring peripheral physiology. Additionally, most of such studies have not considered the specific stimuli content, even though prior literature has shown relevant differences in psychophysiological and subjective responses depending on picture categories. The current study assessed several peripheral correlates (startle amplitude, electrodermal changes, heart rate) of emotion regulation processes in a sample of 122 healthy participants. The task consisted of voluntary reappraisal of negative emotions prompted by unpleasant pictures (threat to others and victims), compared to a nonregulation control condition (looking at exemplars of the same categories and household objects). Results showed an effect of emotion regulation instructions in all psychophysiological and subjective measures. In peripheral physiology, greater responses were observed specifically when increasing negative emotions, concurring with previous research. Regarding specific content, our findings evidence a similar emotion regulation pattern, independently of the unpleasant category, suggesting a plausible effect of cognitive variables (such as cognitive effort) during voluntary reappraisal for both categories.     

Probing picture perception: Activation and emotion

When acoustic startle probes are presented during picture viewing, the blink reflex is augmented for unpleasant foreground stimuli and reduced during pleasant stimuli. The present experiment assessed the hypothesis that this affect-Startle effect increases as pictures are judged to be more arousing. Eyeblinks elicited by startle probes of three different intensities were recorded while subjects viewed pictures varying in both pleasure (pleasant, neutral, and unpleasant) and arousal (low, moderate, and high). Both blink potentiation during unpleasant content and blink diminution during pleasant content were clearly strongest for picture contents high in arousal. The effect was present for all probe intensities tested.     

Loss of emotional experience after traumatic brain injury: findings with the startle probe procedure

The authors used affective modulation of the eyeblink startle response to examine the impact of traumatic brain injury (TBI) on emotional reactions to pictures. Participants were 13 individuals with severe TBI and 24 controls. Participants were presented with pictures that differed in affective valence (e.g., mutilated bodies, erotic couples, and household objects) while the eyeblink startle response to an acoustic probe was measured. Startle amplitude was used to assess valence of emotional response, and startle latency was used to index interest in the pictures. Subjective ratings of the affect and arousal elicited by the various pictures were also obtained. TBI impaired startle potentiation to unpleasant pictures but not startle attenuation to pleasant pictures. Further, subjective ratings indicated that TBI participants found unpleasant pictures less arousing than did controls. The results are consistent with recent evidence of differential impairment in negative versus positive emotions after TBI and are discussed in relation to 2 competing explanations of startle modulation.     

Affective startle modulation in anticipation and perception

Startle modulation was investigated as participants first anticipated and then viewed affective pictures in order to determine whether affective modulation of the startle reflex is similar in these different task contexts. During a 6-s anticipation period, a neutral light cue signaled whether the upcoming picture would portray snakes, erotica, or household objects; at the end of the anticipatory period, a picture in the signaled category was viewed for 6 s. Male participants highly fearful of snakes were recruited to maximize emotional arousal during anticipation and perception. Results indicated that the startle reflex was potentiated when anticipating either unpleasant (phobic) or pleasant (erotic) pictures, compared to neutral stimuli, whereas during perception, reflexes were potentiated when viewing unpleasant stimuli, and reduced when viewing pleasant pictures. The startle reflex is modulated by hedonic valence in picture perception, and by emotional arousal in a task context involving picture anticipation.     

Postauricular reflexes elicited by soft acoustic clicks and loud noise probes: Reliability,prepulse facilitation,and sensitivity to picture contents

The startle blink reflex is facilitated during early picture viewing, then inhibited by attention during pleasant and aversive pictures compared to neutral pictures, and finally potentiated during aversive pictures specifically. However, it is unclear whether the postauricular reflex, which is elicited by the same loud acoustic probe as the startle blink reflex but enhanced by appetitive instead of defensive emotion, has the same pattern and time course of emotional modulation. We examined this issue in a sample of 90 undergraduates using serially presented soft acoustic clicks that elicited postauricular (but not startle blink) reflexes in addition to standard startle probes. Postauricular reflexes elicited by both clicks and probes correlated during food and nurturant contents, during which they were potentiated compared to neutral pictures, suggesting clicks effectively elicit emotionally modulated postauricular reflexes. The postauricular reflex was initially facilitated during the first 500 ms of picture processing but was larger during pleasant than neutral pictures throughout picture processing, with larger effect sizes during the latter half of picture processing. Across reflexes and eliciting stimuli, measures of emotional modulation had higher coefficient alphas than magnitudes during specific picture contents within each valence, indicating that only emotional modulation measures assess higher‐order appetitive or defensive processing.     

Pictures as prepulse: Attention and emotion in startle modification

The effects of an emotional stimulus prepulse on probe startle response were examined here. Pleasant, neutral, and unpleasant pictures were viewed for 6 s, and an acoustic startle probe was presented either 300, 800, 1,300, or 3,800 ms after slide onset, or 300 or 3,800 ms after slide offset. Blink magnitude and onset latency demonstrated (a) an early (prepulse) inhibition effect in which reflexes elicited immediately after slide onset were smaller than reflexes elicited later in the viewing interval, and (b) affective modulation, in which unpleasant stimuli prompted larger reflexes than pleasant. Interactive effects of probe time and picture valence indicated attention/arousal effects early and pleasantness effects late in the picture interval. Effects of both attention and emotion can be simultaneously measured using this startle-probe paradigm, encouraging its use in both basic and clinical contexts.     

Startle modulation before, during and after exposure to emotional stimuli.

Although affective modulation of the startle reflex is a highly replicable effect, the majority of studies have administered startle probes during exposure to affective stimuli. To examine more comprehensively the temporal course of startle potentiation, we assessed blink modulation before, during and immediately after exposure to positive, negative and neutral pictures. During each trial, cues about the affective content of pictures were presented, after which acoustic startle probes were delivered either before picture onset, during picture onset or immediately after picture offset. As expected, we observed a linear relation between picture valence and startle amplitude during picture viewing. Surprisingly, startle amplitude was larger while anticipating pleasant and unpleasant pictures relative to neutral pictures. No significant effects were observed during the offset phase. These results indicate that startle modulation is conditional upon temporal factors linked to stimulus onset and offset.     

Affective picture modulation: valence, arousal, attention allocation and motivational significance

The present study analyses the modulatory effects of affective pictures in the early posterior negativity (EPN), the late positive potential (LPP) and the human startle response on both the peripheral (eye blink EMG) and central neurophysiological levels (Probe P3), during passive affective pictures viewing. The affective pictures categories were balanced in terms of valence (pleasant; unpleasant) and arousal (high; low). The data shows that EPN may be sensitive to specific stimulus characteristics (affective relevant pictures versus neutral pictures) associated with early stages of attentional processing. In later stages, the heightened attentional resource allocation as well as the motivated significance of the affective stimuli was found to elicit enhanced amplitudes of slow wave processes thought to be related to enhanced encoding, namely LPP,. Although pleasant low arousing pictures were effective in engaging the resources involved in the slow wave processes, the highly arousing affective stimuli (pleasant and unpleasant) were found to produce the largest enhancement of the LPP, suggesting that high arousing stimuli may are associated with increased motivational significance. Additionally the response to high arousing stimuli may be suggestive of increased motivational attention, given the heightened attentional allocation, as expressed in the P3 probe, especially for the pleasant pictures. The hedonic valence may then serve as a mediator of the attentional inhibition to the affective priming, potentiating or inhibiting a shift towards defensive activation, as measured by the startle reflex.     

Temporal course of emotional startle modulation in schizophrenia patients.

The temporal course of startle reflex modulation to emotional pictures was investigated in 49 relatively asymptomatic schizophrenia outpatients and 46 normal controls. Participants viewed pleasant, neutral and unpleasant pictures, which were presented for 6 s and acoustic startle probes were delivered at five different times after picture onset. Replicating previous findings schizophrenia patients showed the same affective modulation of the startle reflex as healthy controls when probes were presented later during the picture-viewing period (3800 ms). For the early probe times (300 and 800 ms), affective pictures proved to be the effective prepulse stimuli resulting in a clear Prepulse inhibition (PPI) effect in both groups. In contrast to previous findings, the PPI of startle response was not stronger during processing emotional stimuli relative to neutral stimuli. For control subjects, blink reflexes were larger for unpleasant pictures compared with neutral and pleasant pictures, representing an early activation of motivational systems. Schizophrenia patients on the other hand, did not show this early affective modulation of the acoustic startle reflex.     

Emotion regulation and potentiated startle across affective picture and threat-of-shock paradigms

Past studies beginning with Jackson et al. [Jackson, D.C., Malmstadt, J.R., Larson, C.L., Davidson, R.J., 2000. Suppression and enhancement of emotional responses to unpleasant pictures. Psychophysiology 37 (4), 515-522.] document increases and decreases in emotionally-potentiated startle by way of instructing participants to enhance or suppress their emotional responses to symbolic sources of threat (unpleasant pictures). The present study extends this line of work to a threat-of-shock paradigm to assess whether startle potentiation elicited by threat of actual danger or pain is subject to emotion regulation. Results point to successful volitional modulation for both Affective-Picture and Threat-of-Shock experiments with startle magnitudes from largest to smallest occurring in the enhance, maintain, and suppress conditions. Successful regulation of startle potentiation to the threat of shock found by the current study supports the external validity of the Jackson paradigm for assessment of regulation processes akin to those occurring in the day-to-day context in response to real elicitors of emotion.     

Emotion and motivated behavior: postural adjustments to affective picture viewing

Thirty-six participants (18 female, 18 male) viewed affective pictures to investigate the coupling between emotional reactions and motivated behavior. Framed within the biphasic theory of emotion, the three systems approach was employed by collecting measures of subjective report, expressive physiology, and motivated behavior. Postural adjustments associated with viewing affective pictures were measured. Results indicated sex-differences for postural responses to unpleasant pictures; an effect not found for pleasant and neutral picture contents. Females exhibited increased postural movement in the posterior direction, and males exhibited increased movement in the anterior direction, for unpleasant pictures. Subjective report of valence and arousal using the self-assessment manikin (SAM), and the startle eye-blink reflex were collected during a separate session, which replicated previous picture-viewing research. Specifically, participants rated pleasant pictures higher in valence and exhibited smaller startle responses compared to unpleasant pictures. Females also reported lower valence ratings compared to males across all picture contents. These findings extend our knowledge of motivated engagement with affective stimuli and indicate that postural responses may provide insight into sex-related differences in withdrawal behavior.     

Emotional modulation of pain-related evoked potentials

To investigate whether cortical processing of trigeminal nociception is modulated by emotion, the N2 and P2 components of the pain-related evoked potential (PREP) were recorded in response to noxious stimulation of the supraorbital nerve while participants viewed neutral, pleasant and unpleasant pictures. The nerve was stimulated at 125% of pain threshold via a nociceptive-specific concentric electrode to selectively activate A-delta pain fibres. The N2 and P2 pain-related evoked potentials were similarly influenced by emotional priming: the amplitude of both potentials decreased monotonically from viewing neutral to pleasant to unpleasant pictures. These findings show that cortical processing of trigeminal nociception is modulated by emotion. We explain our findings in terms of the effects of picture viewing on attention.     

Probe P3 and blinks: Two measures of affective startle modulation

Two concurrent measures of the evoked startlé response, the elicited blink reflex and the event-related potential, were measured while individuals viewed pictures that varied in pleasure and arousal. Replicating previous findings, the blink response was modulated by picture pleasantness, with larger reflexes elicited in the context of viewing unpleasant versus pleasant pictures. However, the probe P3 was primarily modulated by picture arousal, with smaller P3 responses elicited when viewing affective (pleasant or unpleasant) than when viewing neutral pictures. Both modulatory effects were sustained for probes presented in a subsequent picture imagery period. These data suggest that two measurable responses to the same startle probe are differentially modified by emotional context, with blink magnitude varying with pleasure and probe P3 varying with stimulus arousal.     

Startle amplitude during unpleasant pictures is greater in veterans with a history of multiple‐suicide attempts and predicts a future suicide attempt

Recent studies demonstrate that veterans exhibit higher suicide risk compared with the general U.S. population. A prior suicide attempt is a well‐documented predictor of suicide death. Despite increased attention to clinical risk factors of suicide and efforts to develop psychosocial interventions to reduce suicide risk, the underlying biological factors that confer this risk are not well understood. This study examined affect‐modulated startle (AMS) during a series of intermixed unpleasant, neutral, and pleasant pictures in a sample of 108 demographically‐matched veterans at low (passive ideators: n = 26) and high risk (active ideators: n = 29; single attempters: n = 28; and multiple attempters: n = 25) for suicide based on the Columbia Suicide Severity Rating Scale. An exploratory aim involved a longitudinal component in a subset of the high‐risk sample that went on to participate in a randomized 6‐month clinical trial. We investigated whether baseline AMS predicts a subsequent suicide attempt at 12‐month follow‐up. Compared with the other three groups, multiple attempters showed greater startle potentiation during unpleasant pictures and deficient overall startle habituation from early to later trials. The groups did not differ in startle during neutral or pleasant pictures, or self‐reported picture valence. Greater startle during unpleasant pictures was associated with greater emotion dysregulation as measured by the Difficulties in Emotion Regulation Scale and a future suicide attempt assessed prospectively at 12‐month follow‐up. These findings suggest that startle potentiation during unpleasant pictures in multiple‐suicide attempters is a promising psychophysiological biomarker of suicide risk and underscore the clinical importance of targeting emotion dysregulation in the treatment of patients at‐risk for suicide.     

Modulation of the ERP repetition effects during exposure to phobia-relevant and other affective pictures in spider phobia

In the present study, dense sensor event-related potentials were measured in spider-phobic individuals and non-anxious controls during incidental encoding of phobia-relevant spider and standard neutral, unpleasant and pleasant pictures. Stimulus repetition effects were assessed by presenting each picture twice--in the first and in the second half of the session. Repeated presentation of standard pleasant, unpleasant and neutral pictures resulted in a late ERP repetition effect that was similarly pronounced in both experimental groups and for all picture categories. Moreover, relative to non-fearful controls spider-phobic individuals showed an overall greater early ERP repetition effect starting at 180 ms after picture onset. At later stages of evaluative processing, repeated as compared with initial presentation of phobia-relevant spider pictures elicited reduced ERP amplitudes over centro-parietal sites (480-580 ms) in spider-phobic but not in control individuals. This pattern of results indicates that in small animal phobics long lasting exposure to their feared pictures leads to an increased mobilization of the perceptual analysis system, an effect that might help to improve emotional control and/or facilitate strategic avoidance of threat resulting in a diminished evaluative threat processing. This phobia-specific processing mechanism might prevent effective stimulus processing and hinder the habituation process during treatment.