Experimental Manipulations of Personal Control do Not Increase Illusory Pattern Perception

Pharmacological Enhancement of Dopamine Neurotransmission Does Not Affect Illusory Pattern Perception

Psychotic symptoms and delusional beliefs have been linked to dopamine transmission in both healthy and clinical samples and are assumed to result at least in part from perceiving illusory patterns in noise. However, the existing literature on the role of dopamine in detecting patterns in noise is inconclusive. To address this issue, we assessed the effect of manipulating dopaminergic neurotransmission on illusory pattern perception in healthy individuals (n = 48, n = 19 female) in a double-blind placebo-controlled within-subjects design (see preregistration at https://osf.io/a4k9j/). We predicted individuals on versus off ʟ-DOPA to be more likely to perceive illusory patterns, specifically objects in images containing only noise. Using a signal detection model, however, we found no credible evidence that ʟ-DOPA compared with placebo increased false alarm rates. Further, ʟ-DOPA did not reliably modulate measures of accuracy, discrimination sensitivity, and response bias. In all cases, Bayesian statistics revealed strong evidence in favor of the null hypothesis. The task design followed previous work on illusory pattern perception and comprised a limited number of items per condition. The results therefore need to be interpreted with caution, as power was limited. Future studies should address illusory pattern perception using more items and take into account potential dose-dependent effects and differential effects in healthy versus clinical samples.

What do we manipulate when reminding people of (not) having control? In search of construct validity

The construct of personal control is crucial for understanding a variety of human behaviors. Perceived lack of control affects performance and psychological well-being in diverse contexts - educational, organizational, clinical, and social. Thus, it is important to know to what extent we can rely on the established experimental manipulations of (lack of) control. In this article, we examine the construct validity of recall-based manipulations of control (or lack thereof). Using existing datasets (Study 1a and 1b: N = 627 and N = 454, respectively) we performed content-based analyses of control experiences induced by two different procedures (free recall and positive events recall). The results indicate low comparability between high and low control conditions in terms of the emotionality of a recalled event, the domain and sphere of control, amongst other differences. In an experimental study that included three types of recall-based control manipulations (Study 2: N = 506), we found that the conditions differed not only in emotionality but also in a generalized sense of control. This suggests that different aspects of personal control can be activated, and other constructs evoked, depending on the experimental procedure. We discuss potential sources of variability between control manipulation procedures and propose improvements in practices when using experimental manipulations of sense of control and other psychological constructs.

Experimental manipulation of uncanny feeling does not increase adherence to conspiracy theories

Research over the past decade has shown that endorsement of conspiracy theories (CTs) is shaped by motivated cognition processes. Accordingly, CTs are theorized to stem from compensatory processes, as individuals attempt to cope with existential threats (i.e., uncertainty, loss of control). Based on the meaning maintenance model, we investigated whether this compensatory effect could follow from epistemic threats in domains unrelated to CTs in the form of uncanniness. Feelings of uncanniness were experimentally manipulated through exposure to absurdist art and literature in a set of five studies, followed by a mini meta-analysis (Ntotal  = 1,041). We conducted a final, preregistered sixth study (N = 266) manipulating uncanniness through autobiographical recall. No robust evidence for a compensatory effect was found. We discussed methodological and conceptual limitations of the meaning maintenance model, as well as boundary conditions under which conspiracy theories could have a compensatory function to deal with threats.

Investigating False Memory and Illusory Pattern Perception Bias in Schizophrenia Patients with and without Delusions

Background

Whether the false memory dysfunction in schizophrenia is at the early (encoding, perceptual) or later (retrieval) stages and how delusions affect it remains unclear.

Method

In this study, we examined the perception and memory biases in schizophrenia patients with (Sch/D; n = 31) and without delusions (Sch/Nd; n = 32) and compared them with healthy controls (HCs; n = 35). We used the Deese Roediger McDermott (DRM) Paradigm and the Noise Task to measure the false memory and illusory pattern perception (IPP) biases, respectively.

Results

We found that the patient groups performed lower in both the recall and recognition phases for the DRM and the Noise tasks and made more errors compared to the HC group. Additionally, the performance of the Sch/D group was remarkably lower than the Sch/Nd and HC groups.

Conclusions

Our results indicated that the information-processing problem in schizophrenia exists in both the encoding and retrieval stages. Also found significant relationship between the presence of delusions and the increase in cognitive deficits.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10608-023-10393-6.

Does the sense of power influence reputational concern? Tests with episodic and semantic power priming