Semantic similarity influences early morphological priming in Serbian: A challenge to form-then-meaning accounts of word recognition

Semantically similar (e.g., coolant-COOL) primes have produced greater facilitation than have form-similar but semantically dissimilar (e.g., rampant-RAMP) primes when English words have appeared in the forward-masked primed lexical decision task (Feldman, O'Connor, & Moscoso del Prado Martín, Psychonomic Bulletin & Review 16: 684-691, 2009). These results challenge claims that form-based, semantically blind activation underlies early morphological facilitation. Some have argued that the English materials in previous studies were not ideally constructed, insofar as the types of spelling changes to affixed stems differed in the semantically similar and dissimilar pairs. The present study exploited Serbian's bialphabetism, rich morphology, and homographic (form-identical) stems to replicate early effects of semantic similarity. Furthermore, it incorporated within-target manipulations of prime type and of alphabet, such that the alphabets of the prime-target pairs matched in Experiment 1a and alternated in Experiment 1b. Importantly, no letter or phoneme changes occurred between the stems of the primes and targets. These results revealed significant effects of semantic similarity that are comparable with and without alphabet alternation. The semantic effects in Serbian replicated almost exactly those in English (Feldman et al., Psychonomic Bulletin & Review 16: 684-691, 2009), which suggests that even early in the course of processing, morphemes are units of meaning as well as of form. The results failed to support models of lexical processing that postulate sequential access, first to the morphological form, and then to the semantic aspects of words.     

Symmetry,complexity and perceptual economy: Effects of minimum and maximum simplicity conditions

According to Gestalt theory, the perceptual system works on economic principles and tends to reach the maximum efficiency (i.e., increase of quality, goodness, and accuracy) with minimum invested energy (i.e., reduction of processing load). In this study the effects of two concurrent stimulus constraints, symmetry and simplicity, were investigated with the following variables related to perceptual economy: Goodness judgement (Experiment 1), completion of semi-structured patterns (Experiment 2), duration of search for target patterns (Experiment 3), and the duration and accuracy of pattern detection (Experiment 4). The results suggest that the dominance of symmetry or simplicity depends upon the difficulty of the experimental task. Symmetry prevailed in less restrictive, more interesting, and easier perceptual tasks, such as goodness judgement and pattern completion (Experiments 1, 2, and, partly, Experiment 3), whereas simplicity prevailed in difficult and restricted conditions, such as the detection of briefly exposed stimuli (50 ms; Experiment 4). The results are discussed in the context of Koffka's concept of minimum and maximum simplicity. When the perceptual system has a small energy disposal, or when external conditions are difficult and restricted (minimum simplicity conditions), simplicity in stimulus pattern organization will be preferred. When the perceptual system has a large amount of energy, or when external situations are unrestricted and interesting (maximum simplicity conditions), fine and regular articulations of stimulus patterns will be preferred. Our study confirmed the prediction implied by the concept of minimum and maximum simplicity.