Phantom phone signals are benign, not an indication of a messed-up mind

Phantom phone signals and other hallucinatory-like experiences: investigation of similarities and differences. Adrianna Aleksandrowicz, Joachim Kowalski, Łukasz Gawęda. Psychiatry Research, November 19 2022, 114964. https://doi.org/10.1016/j.psychres.2022.114964

Abstract: Phantom Phone Signals (PPS) and other hallucinatory-like experiences (HLEs) are perceptual anomalies that are commonly reported in the general population. Both phenomena concern the same sensory modality, but PPS are restricted to smartphone use. The current study aimed to assess similarities and differences between these types of anomalies in relation to general psychopathology, metacognitive beliefs about perception, smartphone dependence, and susceptibility to top-down influences on perception. We analyzed data from a Polish community sample (N = 236, aged 18–69). We used questions pertaining to PPS, a questionnaire pertaining to HLEs (Multi-Modality Unusual Sensory Experiences Questionnaire), and other variables of interest (Symptom Checklist-27-plus, Mobile Phone Problematic Use Scale, and the Beliefs about Perception Questionnaire). Additionally, a false-perception task manipulating cognitive expectancy (i.e., a visual cue associated with auditory stimuli vs. no visual cue) was devised to measure top-down influences on perception. Regression analyses showed that only top-down beliefs about perception predicted both PPS and HLEs. Smartphone dependency proved to be a stronger predictor of PPS than other measured variables, whereas for HLEs, general psychopathology was the strongest predictor. Current results suggest that despite sharing some mechanisms, PPS and HLEs may have independent underlying factors.

Introduction

Hallucinations are a key symptom in the diagnosis of schizophrenia spectrum disorders. It is estimated that hallucinations occur in approximately 80% of patients with schizophrenia spectrum disorders, with the most common being auditory hallucinations (Toh et al., 2022). According to the continuum hypothesis, hallucinations in the clinical context are considered as an extreme manifestation of phenomena that range from vivid daydreams, through infrequent experiences of different sounds (e.g., mistakenly hearing one's name being called) to full-blown hallucinations (e.g., hearing distressing voices). Yet, a significant body of work has shown that hallucinatory-like experiences (HLEs), which lie on the hallucination continuum, are frequently reported in the non-clinical population (Linszen et al., 2022). It has been suggested that auditory hallucinations occur in 13.2% of the general population (Beavan et al., 2011). These data suggest that HLEs and hallucinations also occur outside the clinical context. Investigation of HLEs in the general population is important, as it helps us better understand the mechanisms underlying hallucinations and other perceptual anomalies (Barkus et al., 2007; Daalman et al., 2010).

Recently, in addition to studies on general HLEs, Phantom Phone Signals (PPS) are being increasingly studied as perceptual phenomena (Drouin et al., 2012; Horga & Abi-Dargham, 2020; Lin, et al., 2013a,b; Lin et al., 2020; Pisano et al., 2019; Tanis et al., 2015). PPS are perceptual anomalies wherein feedback from phones is experienced without having occurred, such as the sensation of a phone ringing, an incoming message, or a notification coming from various applications. PPS are experienced in auditory (as a ringing phone), visual (a blinking notification displayed on a smartphone screen), and tactile (phantom vibration) modalities (Tanis et al., 2015). It is estimated that between 27.4% and 89% of people from the general population experience PPS (Deb, 2015; Pisano et al., 2021). This relatively high prevalence suggests that PPS are a common experience and may be associated with the growing usage of smartphones (Pisano et al., 2021). Indeed, it is estimated that about 3.5 billion people worldwide use smartphones (O'Dea, 2020). In 2018 in Poland, almost 80% of the population used smartphones (Mobirank, 2020), and 74.8% of all cell-phone users did so on a daily basis. Importantly, cellphone addiction is rising alongside smartphone usage (Olson et al., 2022). Thus, PPS and associated phenomena are becoming an important field of research.

Previous studies have shown that some characteristics of smartphone usage are predictors of experiencing PPS (Rothberg et al., 2010; Subba, 2013; Tanis et al., 2015). A study conducted by Al-Ani et al. (2009) showed that PPS experiences were very common among participants who rated themselves as “mobile addicted.” Moreover, another study also provided evidence of a significant relationship between PPS and excessive smartphone usage, smartphone addiction, and phone importance (Tanis et al., 2015). Still, some studies found that characteristics of smartphone usage are not related to PPS (Catchings et al., 2010). It should be noted that conclusions from studies that link PPS to characteristics of smartphone usage are limited by the low number of studies. For this reason, further studies on the mechanisms of PPS are needed.

With regard to the mechanisms of PPS, some studies reported that contextual factors, such as expecting a call or being in a noisy environment, are important in reinforcing the experience of PPS (Sauer et al., 2015). For instance, being in a workplace where smartphones are essential for communicating with co-workers has been shown to reinforce the occurrence of PPS. A study on medical students showed a substantial change in experiences of PPS during a medical internship. For instance, at baseline, 78.1% students reported phantom vibrations and 27.4% reported phantom ringing. At follow-up, these rates increased to 95.9% and 87.7% respectively (Lin, et al., 2013b). Although the evidence indicates a high prevalence of PPS among medical students, more research on the general population is still needed (Pisano et al., 2021).

Importantly, although PPS have been found to correlate with high stress levels, anxiety, and depressive symptoms (Lin, et al., 2013a,b; Lin et al., 2020), few studies have focused on the relationships between PPS and psychopathology (Pisano et al., 2021). One study among adolescents found a relationship between experiencing PPS and both emotional problems and temper tantrums (Pisano et al., 2019). At the same time, the association between a wide range of HLEs and psychopathology is well documented (Allen et al., 2005; Gaweda et al., 2012; Johns, 2005). Additionally, the cognitive mechanisms of HLEs have been investigated in a rich line of research. For instance, attentional processes, cognitive control (Conn & Posey, 2000; Hugdahl et al., 2013), as well as different cognitive biases have been found to be important factors related to HLEs. With regard to PPS, there is much less research on cognitive mechanisms associated with this phenomenon.

One of the leading theoretical accounts suggests that perceptual anomalies are the result of an imbalance between top-down processes (i.e., priors or cognitive expectancy) and bottom-up processes. The role of top-down processes in shaping percepts is particularly emphasized in situations of perceptual uncertainty, where cognitive expectancy can influence the final percept (Corlett et al., 2019; Horga & Abi-Dargham, 2020; Powers et al., 2016). Cognitive expectancy may be considered as a prior that impacts perception (Corlett et al., 2019). It has been shown that priors have a stronger impact on perception in people who hallucinate than those without hallucinations (Powers et al., 2016). Thus, this suggests that cognitive expectancy (i.e., priors) may have an important impact on perception. Similarly, regarding PPS, it has been proposed that these experiences may emerge from the anticipation of phone signals through expectations (Rothberg et al., 2010). For instance, PPS may emerge in the context of a belief that the phone should ring because one is waiting on an important phone call. A limited number of studies have investigated this account in the context of semantic expectancy and its relationship to HLEs (Vercammen & Aleman, 2010). More recently, a study by Gawęda & Moritz (2021) suggested that audiovisual integration might play an essential role in the formation of false percepts in patients with schizophrenia. Participants performed a task in which they were asked to detect a target word in a noisy background (the word was audible in 60% of cases and absent in 40%). Conditions consisted of three levels of expectancy (1. low – no cue prior to the stimulus; 2. medium – semantic priming; 3. high – semantic priming accompanied by a video of a man mouthing the word). The results indicated that higher expectancy significantly increased the likelihood of false auditory perceptions among schizophrenia patients only. This gives preliminary evidence that the visual modality might play an important role in the complex mechanisms of auditory perceptual anomalies. Nonetheless, more research on visual and auditory modalities in the context of hallucinations and the hallucination continuum is needed.

To date, PPS and other HLEs have been studied independently. A growing line of research investigates PPS as an isolated type of experience without comparison to other HLEs. Therefore, the main aim of our study was to compare PPS and other types of HLEs with general psychopathology, smartphone dependence, and attentional control to investigate their similarities and differences in the non-clinical population. Furthermore, we also considered the relationships of both PPS and HLEs with priors (i.e., top-down factors, such as knowledge and beliefs), which have been linked to perceptual anomalies (Corlett et al., 2019; Horga & Abi-Dargham, 2020; Powers et al., 2016). In our study, we conceptualized priors as meta-cognitive beliefs about perception (Gawęda et al., in preparation). We hypothesized that meta-cognitive beliefs about perception and interpretations of perceptual experiences may tentatively influence how perception operates, and conversely actual perceptual experiences may shape individuals’ beliefs about perceptions. Hence, we expected that there would be a relationship between false perceptions and meta-cognitive beliefs about perception. Moreover, despite some existing research investigating the potential predictors of PPS (Drouin et al., 2012; Horga & Abi-Dargham, 2020; Lin et al., 2013a,b; Lin et al., 2020; Pisano et al., 2019; Tanis et al., 2015), to our knowledge, there are no studies that explore in-depth the mechanisms of this phenomenon using an experimental approach. Therefore, the objective of our study was to experimentally verify the effect of top-down processes on false auditory perceptions using a False Perception Task design (Gawęda & Moritz, 2021). Our experimental task was tailored to examine perceptual experiences that are contextually related to smartphone use (e.g., the moment of an incoming smartphone notification on the screen) with two conditions of expectancy: low (no visual cue associated with an auditory stimuli) and high (a visual cue associated with an auditory stimulus). We hypothesize that more false recognitions will occur in the high expectancy condition than in the low expectancy condition. To our knowledge, this is the first study to investigate experimentally-induced false perceptions that are contextually connected to PPS. Moreover, we aimed to investigate whether there is a relationship between experimentally-induced false perceptions in the context of social media use and PPS alongside other HLEs.