If a mental image is a rerepresentation of a perception, then properties such as luminance or brightness should also be conjured up in the image. We monitored pupil diameters with an infrared eye ...tracker while participants first saw and then generated mental images of shapes that varied in luminance or complexity, while looking at an empty gray background. Participants also imagined familiar scenarios (e.g., a "sunny sky" or a "dark room") while looking at the same neutral screen. In all experiments, participants' eye pupils dilated or constricted, respectively, in response to dark and bright imagined objects and scenarios. Shape complexity increased mental effort and pupillary sizes independently of shapes' luminance. Because the participants were unable to voluntarily constrict their eyes' pupils, the observed pupillary adjustments to imaginary light present a strong case for accounts of mental imagery as a process based on brain states similar to those that arise during perception.
•Music chills are bodily responses corresponding to peak emotional experiences.•Chills are reported more frequently for self-selected songs than songs selected by others.•Pupil size was larger within ...specific time-windows around the chill events.•Pupil size increase both in an active (key response) and passive (simply listening) conditions.•A neuromodulatory role of the central norepinephrine system is implicated in this phenomenon.
This study evaluated whether music-induced aesthetic “chill” responses, which typically correspond to peak emotional experiences, can be objectively monitored by degree of pupillary dilation. Participants listened to self-chosen songs versus control songs chosen by other participants. The experiment included an active condition where participants made key presses to indicate when experiencing chills and a passive condition (without key presses). Chills were reported more frequently for self-selected songs than control songs. Pupil diameter was concurrently measured by an eye-tracker while participants listened to each of the songs. Pupil size was larger within specific time-windows around the chill events, as monitored by key responses, than in comparison to pupil size observed during ‘passive’ song listening. In addition, there was a clear relationship between pupil diameter within the chills-related time-windows during both active and passive conditions, thus ruling out the possibility that chills-related pupil dilations were an artifact of making a manual response. These findings strongly suggest that music chills can be visible in the moment-to-moment changes in the size of pupillary responses and that a neuromodulatory role of the central norepinephrine system is thereby implicated in this phenomenon.
Opposing forces influence assortative mating so that one seeks a similar mate while at the same time avoiding inbreeding with close relatives. Thus, mate choice may be a balancing of phenotypic ...similarity and dissimilarity between partners. In the present study, we assessed the role of resemblance to Self's facial traits in judgments of physical attractiveness. Participants chose the most attractive face image of their romantic partner among several variants, where the faces were morphed so as to include only 22% of another face. Participants distinctly preferred a "Self-based morph" (i.e., their partner's face with a small amount of Self's face blended into it) to other morphed images. The Self-based morph was also preferred to the morph of their partner's face blended with the partner's same-sex "prototype", although the latter face was ("objectively") judged more attractive by other individuals. When ranking morphs differing in level of amalgamation (i.e., 11% vs. 22% vs. 33%) of another face, the 22% was chosen consistently as the preferred morph and, in particular, when Self was blended in the partner's face. A forced-choice signal-detection paradigm showed that the effect of self-resemblance operated at an unconscious level, since the same participants were unable to detect the presence of their own faces in the above morphs. We concluded that individuals, if given the opportunity, seek to promote "positive assortment" for Self's phenotype, especially when the level of similarity approaches an optimal point that is similar to Self without causing a conscious acknowledgment of the similarity.
Preference for phenotypic similarity in assortative mating may be influenced by either a preference for self-similarity or parent-similarity. The aim of the current study was to assess whether ...people's preference in face attractiveness is influenced by resemblance to the opposite sex parent's face (parental phenotype) or their own face (self-based phenotype or "self-imprinting"). We used computerized image manipulations of facial photographs of participants, their mothers and fathers. The original photographs were combined with 78% of the participants' opposite sex prototype face (i.e., male and female prototypes made from equal contributions of a hundred faces), creating morphs where the contribution from the familiar faces went unnoticed. Female and male participants ranked these images together with the opposite-sex prototype different familiar morphs. Each participant did the same for the morphs generated with other same-sex participants' faces and of their parents. We found that the female participants preferred the self-based morphs to the prototype faces. Male participants showed a general tendency towards self-referential standard. Parental face morphs were ranked low in attractiveness, which may be accounted for by the age difference of the faces blended into the self-based versus parental face morphs, since we used present-time photographs of both the participants and their parents.
Pupillary responses and associated vergence eye movements were monitored during imagery of objects of differing sizes (“large” or “small”) from varying distances (“near” or “far”). Objects’ imagined ...size and distance affected oculomotor behavior. Objects visualized as “far” resulted in the larger pupil dilations and smaller visual angle, while small objects imagined “near” were associated with smaller pupils in contrast to relatively larger pupils when imagined as “far” away. Furthermore, near objects resulted in larger visual angle, and particularly, vergence adjustments were observed that were dependent on imagined size and distance of the small objects. The findings are consistent with the idea that imagery emulates perception, also at the embodied level of oculomotor behaviors.
Dilating the pupils allow more quanta of light to impact the retina. Consequently, if one pupil is dilated with a pharmacological agent (Tropicamide), the brightness of a surface under observation ...should increase proportionally to the pupil dilation. Little is known about causal effects of changes in pupil size on perception of an object’s brightness. In a psychophysical procedure of brightness adjustment and matching, we presented to one eye geometrical patterns with a central square (the reference pattern) that differed in physical brightness within backgrounds of constant luminance. Subsequently, with the other eye, participants (n = 30) adjusted to the same luminance a similar pattern (target) whose central square luminance was randomly set higher or lower in brightness than the reference. As only one eye was treated with Tropicamide, we assessed whether the subjective brightness of the target square shifted in a consistent direction when viewed with the dilated pupil compared to the untreated (control) eye. We found that, as the pupil increased post drug administration, so significantly did the sense of brightness of the pattern (i.e., higher brightness adjustments followed viewing the reference pattern with the treated (Tropicamide) eye). A reversed effect was observed when the control eye viewed the reference pattern first. The results confirm that even slight pupil dilations can result in an enhanced perceptual experience of brightness of the attended object, corresponding to an average increase of 2.09 cd/m2 for each 1 mm increase in pupil diameter.
Opposing forces influence assortative mating so that one seeks a similar mate while at the same time avoiding inbreeding with close relatives. Thus, mate choice may be a balancing of phenotypic ...similarity and dissimilarity between partners. In the present study, we assessed the role of resemblance to Self's facial traits in judgments of physical attractiveness. Participants chose the most attractive face image of their romantic partner among several variants, where the faces were morphed so as to include only 22% of another face. Participants distinctly preferred a "Self-based morph" (i.e., their partner's face with a small amount of Self's face blended into it) to other morphed images. The Self-based morph was also preferred to the morph of their partner's face blended with the partner's same-sex "prototype", although the latter face was ("objectively") judged more attractive by other individuals. When ranking morphs differing in level of amalgamation (i.e., 11% vs. 22% vs. 33%) of another face, the 22% was chosen consistently as the preferred morph and, in particular, when Self was blended in the partner's face. A forced-choice signal-detection paradigm showed that the effect of self-resemblance operated at an unconscious level, since the same participants were unable to detect the presence of their own faces in the above morphs. We concluded that individuals, if given the opportunity, seek to promote "positive assortment" for Self's phenotype, especially when the level of similarity approaches an optimal point that is similar to Self without causing a conscious acknowledgment of the similarity.
Objective: Children frequently report a heightened experience of psychological problems such as depression, anxiety, aggression, and posttraumatic stress disorder in response to maltreatment. ...However, in recent years, scholars have suggested that different types of maltreatment may be associated with different symptomatology in children. Method: In the present study, we employ the Trauma Symptom Checklist for Young Children (TSCYC) to investigate whether children who have experienced different types of maltreatment reveal different profiles of symptomatology. Nonmaltreated (n = 101) and maltreated (n = 52) children between 3 and 12 years of age were included in the present study. Maltreatment was further categorized into the subgroups abuse and neglect. Results: Findings proved the TSCYC to be successful in distinguishing nonmaltreated from maltreated children in terms of symptomatology. Furthermore, abused children showed a broader spectrum of symptoms, whereas neglected children differed on fewer symptom scales compared with their nonmaltreated peers. Lastly, abused children evinced more externalizing symptoms than the neglected children. Conclusion: In line with previous research, maltreated children do have more psychological symptoms, and, abused children showed enhanced psychological problems and more externalizing symptoms in particular.