Every rose has its thorn: Infants' responses to pointed shapes in naturalistic contexts

Implicit and explicit safety evaluation of foods: The importance of food processing

Identifying beneficial foods in the environment, while avoiding ingesting something toxic, is a crucial task humans face on a daily basis. Here we directly examined adults' implicit and explicit safety evaluations of the same foods presented with different degrees of processing, ranging from unprocessed (raw) to processed (cut or cooked). Moreover, we investigated whether individual characteristics (e.g., Body Mass Index, food neophobia and hunger) modulated their evaluations. We hypothesized that adults would associate the processed form of a food with safety more than its unprocessed form since processing techniques, which are ubiquitously applied in different cultures, often reduce the toxicity of foods, and signal previous human intervention and intended consumption. Adults (N = 109, 43 females) performed an implicit Go/No-Go association task (GNAT) online, assessing the association between safety attributes and food images differing on their degree of processing, both unfamiliar and familiar foods were used. Then each food was explicitly evaluated. Results revealed that individual self-reported characteristics affected both implicit and explicit evaluations. Individuals with excess weight and obesity had a strong and positive implicit association between processed foods and safety attributes, but explicitly rated cooked foods as the least safe overall, this latter result was found in highly neophobic individuals as well. Yet, at the explicit level, when looking at unfamiliar foods only, processed foods were rated safer than unprocessed foods by all participants. Our results are the first evidence that directly highlights the relevance of the degree of processing in food safety evaluation and suggest that thinking of the important tasks humans face regarding food selection enriches our understanding of food behaviors.

Visual segmentation of complex naturalistic structures in an infant eye-tracking search task

An infant’s everyday visual environment is composed of a complex array of entities, some of which are well integrated into their surroundings. Although infants are already sensitive to some categories in their first year of life, it is not clear which visual information supports their detection of meaningful elements within naturalistic scenes. Here we investigated the impact of image characteristics on 8-month-olds’ search performance using a gaze contingent eye-tracking search task. Infants had to detect a target patch on a background image. The stimuli consisted of images taken from three categories: vegetation, non-living natural elements (e.g., stones), and manmade artifacts, for which we also assessed target background differences in lower- and higher-level visual properties. Our results showed that larger target-background differences in the statistical properties scaling invariance and entropy, and also stimulus backgrounds including low pictorial depth, predicted better detection performance. Furthermore, category membership only affected search performance if supported by luminance contrast. Data from an adult comparison group also indicated that infants’ search performance relied more on lower-order visual properties than adults. Taken together, these results suggest that infants use a combination of property- and category-related information to parse complex visual stimuli.

Learning blossoms: Caregiver-infant interactions in an outdoor garden setting

Plants provide unique opportunities for learning by engaging all human senses. Recent laboratory studies have shown that infants use a combination of behavioural avoidance and social learning strategies to safely learn about plant properties from adults. Here we investigate how infants and their caregivers interact with plants in an outdoor garden as a first step towards examining the operation of these social learning processes in naturalistic settings. We focus on two specific aspects of spontaneous infant-caregiver interactions with plants: olfactory and touch behaviours. Additionally, we look at whether infants' and caregivers' prior knowledge of the plants in our study influences infants' behaviour. Our results showed a multifaceted connection between infants' and caregivers' previous experience with the plants and their olfactory and touch behaviours. First, infants tended to touch and smell the plants after their caregivers did, and this appeared to be independent of whether infants had seen the plant before. Second, infants systematically engaged in some of the same types of olfactory and touch behaviours their caregiver displayed towards plants. Finally, infants whose caregivers were given more information about the plants in the study showed fewer touch behaviours, but no difference in olfactory behaviours. These findings bolster the previous laboratory studies of plant learning early in life, highlighting the importance of olfactory behaviours, and underscoring the benefits of using ecological observations to explore unique aspects of human development.

Habitat selection and human aesthetic responses to flowers

Although the aesthetic appreciation of flowers is a well-known aspect of human behaviour, theories explaining its origin are missing. The only exception is the evolutionary theory of Heerwagen and Orians. Surprisingly, it has not yet been empirically tested. The authors suggest that humans aesthetically respond to flowers because they signal food availability. The logic of the theory implies that fruits are more reliable and direct food availability signals than flowers. Therefore, fruits should elicit stronger aesthetic responses than flowers. To test this assumption, we performed two online studies in the Czech Republic. The participants (n = 2792 and 744, respectively) indicated on a six-point scale their aesthetic response to photographs of 14 edible Czech plant species (study A) and 20 edible plant species from the African savannas (study B), varying in growth stage (flowering, fruiting). We found no difference between the Czech fruiting and flowering plants and a stronger aesthetic response to African flowering plants. A third study (n = 817) confirmed that flowers were preferred to fruits, using a forced-choice paradigm. Our results suggest that the theory cannot fully explain human aesthetic responses to flowers. We discuss alternative explanations. This topic deserves renewed attention from researchers working in related fields.