A Prime Example of the Maluma/Takete Effect? Testing for Sound Symbolic Priming

Episodic long-term memory formation during slow-wave sleep

We are unresponsive during slow-wave sleep but continue monitoring external events for survival. Our brain wakens us when danger is imminent. If events are non-threatening, our brain might store them for later consideration to improve decision-making. To test this hypothesis, we examined whether novel vocabulary consisting of simultaneously played pseudowords and translation words are encoded/stored during sleep, and which neural-electrical events facilitate encoding/storage. An algorithm for brain-state-dependent stimulation selectively targeted word pairs to slow-wave peaks or troughs. Retrieval tests were given 12 and 36 hr later. These tests required decisions regarding the semantic category of previously sleep-played pseudowords. The sleep-played vocabulary influenced awake decision-making 36 hr later, if targeted to troughs. The words' linguistic processing raised neural complexity. The words' semantic-associative encoding was supported by increased theta power during the ensuing peak. Fast-spindle power ramped up during a second peak likely aiding consolidation. Hence, new vocabulary played during slow-wave sleep was stored and influenced decision-making days later.

The maluma/takete effect is late: No longitudinal evidence for shape sound symbolism in the first year

The maluma/takete effect refers to an association between certain language sounds (e.g., /m/ and /o/) and round shapes, and other language sounds (e.g., /t/ and /i/) and spiky shapes. This is an example of sound symbolism and stands in opposition to arbitrariness of language. It is still unknown when sensitivity to sound symbolism emerges. In the present series of studies, we first confirmed that the classic maluma/takete effect would be observed in adults using our novel 3-D object stimuli (Experiments 1a and 1b). We then conducted the first longitudinal test of the maluma/takete effect, testing infants at 4-, 8- and 12-months of age (Experiment 2). Sensitivity to sound symbolism was measured with a looking time preference task, in which infants were shown images of a round and a spiky 3-D object while hearing either a round- or spiky-sounding nonword. We did not detect a significant difference in looking time based on nonword type. We also collected a series of individual difference measures including measures of vocabulary, movement ability and babbling. Analyses of these measures revealed that 12-month olds who babbled more showed a greater sensitivity to sound symbolism. Finally, in Experiment 3, we had parents take home round or spiky 3-D printed objects, to present to 7- to 8-month-old infants paired with either congruent or incongruent nonwords. This language experience had no effect on subsequent measures of sound symbolism sensitivity. Taken together these studies demonstrate that sound symbolism is elusive in the first year, and shed light on the mechanisms that may contribute to its eventual emergence.

I don't see what you're saying: The maluma/takete effect does not depend on the visual appearance of phonemes as they are articulated

In contrast to the principle of arbitrariness, recent work has shown that language can iconically depict referents being talked about. One such example is the maluma/takete effect: an association between certain phonemes (e.g., those in maluma) and round shapes, and other phonemes (e.g., those in takete and spiky shapes). An open question has been whether this association is crossmodal (arising from phonemes' sound or kinesthetics) or unimodal (arising from phonemes' visual appearance). In the latter case, individuals may associate a person's rounded lips as they pronounce the /u/ in maluma with round shapes. We examined this hypothesis by having participants pair nonwords with shapes in either an audio-only condition (they only heard nonwords) or an audiovisual condition (they both heard nonwords and saw them articulated). We found no evidence that seeing nonwords articulated enhanced the maluma/takete effect. In fact, there was evidence that it decreased it in some cases. This was confirmed with a Bayesian analysis. These results eliminate a plausible explanation for the maluma/takete effect, as an instance of visual matching. We discuss the alternate possibility that it involves crossmodal associations.

Iconicity in Word Learning and Beyond: A Critical Review

Interest in iconicity (the resemblance-based mapping between aspects of form and meaning) is in the midst of a resurgence, and a prominent focus in the field has been the possible role of iconicity in language learning. Here we critically review theory and empirical findings in this domain. We distinguish local learning enhancement (where the iconicity of certain lexical items influences the learning of those items) and general learning enhancement (where the iconicity of certain lexical items influences the later learning of non-iconic items or systems). We find that evidence for local learning enhancement is quite strong, though not as clear cut as it is often described and based on a limited sample of languages. Despite common claims about broader facilitatory effects of iconicity on learning, we find that current evidence for general learning enhancement is lacking. We suggest a number of productive avenues for future research and specify what types of evidence would be required to show a role for iconicity in general learning enhancement. We also review evidence for functions of iconicity beyond word learning: iconicity enhances comprehension by providing complementary representations, supports communication about sensory imagery, and expresses affective meanings. Even if learning benefits may be modest or cross-linguistically varied, on balance, iconicity emerges as a vital aspect of language.

Cross-Modal Correspondence Between Speech Sound and Visual Shape Influencing Perceptual Representation of Shape: the Role of Articulation and Pitch

Cross-modal correspondence is the tendency to systematically map stimulus features across sensory modalities. The current study explored cross-modal correspondence between speech sound and shape (Experiment 1), and whether such association can influence shape representation (Experiment 2). For the purpose of closely examining the role of the two factors - articulation and pitch - combined in speech acoustics, we generated two sets of 25 vowel stimuli - pitch-varying and pitch-constant sets. Both sets were generated by manipulating articulation - frontness and height of the tongue body's positions - but differed in terms of whether pitch varied among the sounds within the same set. In Experiment 1, participants made a forced choice between a round and a spiky shape to indicate the shape better associated with each sound. Results showed that shape choice was modulated according to both articulation and pitch, and we therefore concluded that both factors play significant roles in sound-shape correspondence. In Experiment 2, participants reported their subjective experience of shape accompanied by vowel sounds by adjusting an ambiguous shape in the response display. We found that sound-shape correspondence exerts an effect on shape representation by modulating audiovisual interaction, but only in the case of pitch-varying sounds. Therefore, pitch information within vowel acoustics plays the leading role in sound-shape correspondence influencing shape representation. Taken together, our results suggest the importance of teasing apart the roles of articulation and pitch for understanding sound-shape correspondence.

A round Bouba is easier to remember than a curved Kiki: Sound-symbolism can support associative memory

Past research has shown that prior knowledge can support our episodic memory for recently encountered associations. According to the model proposed by Cox and Criss (Proceedings of the 40th Annual Conference of the Cognitive Science Society, pp. 250-255, Madison, MI: Cognitive Science Society, 2018) and Cox and Shiffrin (Cognitive Psychology, 97, 31-61, 2017), any features shared by associated items should facilitate encoding and retrieval. We implemented a strict test of this prediction by taking advantage of sound-symbolism associations; here, the latter refer to relationships between phonemes and object characteristics - relationships that participants readily find natural - even if they have never encountered the items before. For instance, the non-word "maluma" is much more readily seen to refer to a random shape with rounded contours than to a shape that has sharp angles. In our study, 70 participants completed paired-associate memory tests after studying lists of three pairs, each composed of a random shape and a non-word. As predicted, there was better associative memory performance for sound-shape pairs that could rely on sound-symbolism links.

Is un stylo sharper than une épée? Investigating the interaction of sound symbolism and grammatical gender in English and French speakers

While the arbitrariness of language has long been considered one of its defining features, there is growing evidence that non-arbitrariness also plays an important role. Here we investigated two sources of non-arbitrariness: systematicity (via grammatical gender) and iconicity (via shape sound symbolism). We manipulated these two elements orthogonally, allowing us to examine the effect of each. In Experiment 1, we found that French speakers associated nonwords containing feminine (masculine) endings with round (sharp) shapes. French speakers also associated nonwords containing round-sounding (sharp-sounding) phonemes with round (sharp) shapes. This was repeated using auditory presentation with both an English-speaking (Experiment 2a) and French-speaking (Experiment 2b) sample. As predicted, the English speakers showed no effects of grammatical gender, while the French speakers did. These results demonstrate that speakers of a language with grammatical gender associate different properties to words belonging to different genders. The results also show that sound symbolism can emerge in stimuli with existing associated information (i.e., endings indicative of grammatical gender, and the association that they evoke). Finally, while previous studies have looked at effects of arbitrary and non-arbitrary mappings contained in a single stimulus, this is the first study to demonstrate that different kinds of non-arbitrary mappings can have an effect when appearing in the same stimulus. Together these results add to our understanding of the importance of non-arbitrariness in language.

The Sound Symbolism of Names

A wealth of research demonstrates that certain language sounds seem to go better with certain kinds of targets (i.e., sound-symbolic associations). The most well-known example is the maluma-takete effect, in which nonwords such as maluma are judged as good matches for round shapes, whereas nonwords such as takete are judged as good matches for sharp shapes. Most of this research involves nonwords, but recent work has shown that sound symbolism has implications for real first names. On the basis of a name’s sound, individuals tend to pair the name with particular shapes and indicate that they prefer people with congruent pairings of name sound and face shape. Individuals also associate different kinds of personalities with given names on the basis of the sounds the names contain. Thus, sound symbolism is not limited to nonwords and can emerge even with words that have existing associations. Sound-symbolic associations may also occur with more abstract properties (e.g., personality traits). Thus, this work provides insight about mechanisms underlying sound-symbolic association.

Assessing sound symbolism: Investigating phonetic forms, visual shapes and letter fonts in an implicit bouba-kiki experimental paradigm

Classically, in the bouba-kiki association task, a subject is asked to find the best association between one of two shapes–a round one and a spiky one–and one of two pseudowords–bouba and kiki. Numerous studies report that spiky shapes are associated with kiki, and round shapes with bouba. This task is likely the most prevalent in the study of non-conventional relationships between linguistic forms and meanings, also known as sound symbolism. However, associative tasks are explicit in the sense that they highlight phonetic and visual contrasts and require subjects to establish a crossmodal link between stimuli of different natures. Additionally, recent studies have raised the question whether visual resemblances between the target shapes and the letters explain the pattern of association, at least in literate subjects. In this paper, we report a more implicit testing paradigm of the bouba-kiki effect with the use of a lexical decision task with character strings presented in round or spiky frames. Pseudowords and words are, furthermore, displayed with either an angular or a curvy font to investigate possible graphemic bias. Innovative analyses of response times are performed with GAMLSS models, which offer a large range of possible distributions of error terms, and a generalized Gama distribution is found to be the most appropriate. No sound symbolic effect appears to be significant, but an interaction effect is in particular observed between spiky shapes and angular letters leading to faster response times. We discuss these results with respect to the visual saliency of angular shapes, priming, brain activation, synaesthesia and ideasthesia.

Five mechanisms of sound symbolic association

Sound symbolism refers to an association between phonemes and stimuli containing particular perceptual and/or semantic elements (e.g., objects of a certain size or shape). Some of the best-known examples include the mil/mal effect (Sapir, Journal of Experimental Psychology, 12, 225-239, 1929) and the maluma/takete effect (Köhler, 1929). Interest in this topic has been on the rise within psychology, and studies have demonstrated that sound symbolic effects are relevant for many facets of cognition, including language, action, memory, and categorization. Sound symbolism also provides a mechanism by which words' forms can have nonarbitrary, iconic relationships with their meanings. Although various proposals have been put forth for how phonetic features (both acoustic and articulatory) come to be associated with stimuli, there is as yet no generally agreed-upon explanation. We review five proposals: statistical co-occurrence between phonetic features and associated stimuli in the environment, a shared property among phonetic features and stimuli; neural factors; species-general, evolved associations; and patterns extracted from language. We identify a number of outstanding questions that need to be addressed on this topic and suggest next steps for the field.