Face and Voice as Social Stimuli Enhance Differential Physiological Responding in a Concealed Information Test

Abstract

Attentional, intentional, and motivational factors are known to influence the physiological responses in a Concealed Information Test (CIT). Although concealing information is essentially a social action closely related to motivation, CIT studies typically rely on testing participants in an environment lacking of social stimuli: subjects interact with a computer while sitting alone in an experimental room. To address this gap, we examined the influence of social stimuli on the physiological responses in a CIT. Seventy-one participants underwent a mock-crime experiment with a modified CIT. In a between-subjects design, subjects were either questioned acoustically by a pre-recorded male voice presented together with a virtual male experimenter’s uniform face or by a text field on the screen, which displayed the question devoid of face and voice. Electrodermal activity (EDA), respiration line length (RLL), phasic heart rate (pHR), and finger pulse waveform length (FPWL) were registered. The Psychopathic Personality Inventory – Revised (PPI-R) was administered in addition. The differential responses of RLL, pHR, and FPWL to probe vs. irrelevant items were greater in the condition with social stimuli than in the text condition; interestingly, the differential responses of EDA did not differ between conditions. No modulatory influence of the PPI-R sum or subscale scores was found. The results emphasize the relevance of social aspects in the process of concealing information and in its detection. Attentional demands as well as the participants’ motivation to avoid detection might be the important links between social stimuli and physiological responses in the CIT.

The Concealed Information Test is Susceptible to Misleading Information

“…Recently, it was proposed that the reactions of different peripheral parameters in the CIT correlate with different subprocesses of it . It was demonstrated that SCR mainly relies on the orienting response, whereas pHR and RLL are closely associated with concealment‐related processes , among which arousal inhibition was underpinned most recently . Yet, it is unknown whether parameters underlying different processes are distinctly susceptible to memory distortions.…”

“…A previous study examining misinformation effects revealed that a very deep encoding of original information weakens the effects of misinformation on memory . To avoid deep encoding, we abstained from employing a mock crime procedure and presented crime‐relevant information in a video instead (see ). Therefore, we interrogated the participants as informed innocents rather than as suspects of the crime.…”

The “Good Cop, Bad Cop” Effect in the RT-Based Concealed Information Test: Exploring the Effect of Emotional Expressions Displayed by a Virtual Investigator

“…Most of the CIT research usually relies on testing subjects in an environment lacking of social stimuli, despite the fact that concealing information is mostly a social action that amplifies the emotional involvement and anticipated consequences for the deceptive agent. [ 36 ] firstly addressed this gap and provided arguments for introducing social stimuli into the CIT. In real life, most interrogations take place in an environment that is saturated with social stimuli.…”

“…Recent studies have shown that arousal [ 41 ], motivation [ 41 – 43 ] and cognitive load [ 22 , 24 , 25 ] may influence one’s performance in concealing information. As Ambach et al [ 36 ] indicated, this influence could go in multiple directions. Firstly, the motivation to remain undetected may be enhanced by the presence of the investigator, but it could also facilitate the motivation to confess.…”

“…In an exploratory study, it has been suggested that the introduction of a virtual investigator in the CIT would lead to an increased involvement and enhanced arousal [ 36 ]. Results confirmed that a uniform male face presentation and voice accompanying each CIT item enhanced differential physiological and behavioral responding to critical items compared to responses to irrelevants.…”