Comparison Stimuli Research Articles

Factors associated with broad binaural pitch fusion in children and adults with hearing aids and cochlear implants

Many hearing-impaired adults who use hearing aids (HAs) and/or cochlear implants (CIs) have broad binaural pitch fusion, such that sounds with large pitch differences are fused across ears (Reiss et al., JARO 2014; JASA). The goal was to determine which subject factors are associated with broad binaural pitch fusion. Binaural pitch fusion was measured in bilateral HA users, bimodal CI users who use a HA in the contralateral ear, and bilateral CI users. Fusion ranges were measured by simultaneous, dichotic presentation of reference and comparison stimuli in opposite ears, and varying the comparison stimulus to find the range that fused with the reference stimulus. Both children (ages 6-9) and adults were tested. Children in the HA and bilateral CI groups had broader fusion than the bimodal CI group. In addition, broad fusion was positively correlated with long durations of HA use and early onset of hearing loss in adult HA users, and negatively correlated with duration of CI use in pediatric bimodal CI users. No correlations with subject factors were seen in bilateral CI users. The findings suggest that type of hearing device experience may influence binaural pitch fusion in hearing-impaired individuals, especially children. [Work supported by NIH-NIDCD grant R01 DC013307.]

Susceptibility to Ebbinghaus and M\xfcller-Lyer illusions in autistic children: a comparison of three different methods

BackgroundStudies reporting altered susceptibility to visual illusions in autistic individuals compared to that typically developing individuals have been taken to reflect differences in perception (e.g. reduced global processing), but could instead reflect differences in higher-level decision-making strategies.MethodsWe measured susceptibility to two contextual illusions (Ebbinghaus, Müller-Lyer) in autistic children aged 6–14 years and typically developing children matched in age and non-verbal ability using three methods. In experiment 1, we used a new two-alternative-forced-choice method with a roving pedestal designed to minimise cognitive biases. Here, children judged which of two comparison stimuli was most similar in size to a reference stimulus. In experiments 2 and 3, we used methods previously used with autistic populations. In experiment 2, children judged whether stimuli were the ‘same’ or ‘different’, and in experiment 3, we used a method-of-adjustment task.ResultsAcross all tasks, autistic children were equally susceptible to the Ebbinghaus illusion as typically developing children. Autistic children showed a heightened susceptibility to the Müller-Lyer illusion, but only in the method-of-adjustment task. This result may reflect differences in decisional criteria.ConclusionsOur results are inconsistent with theories proposing reduced contextual integration in autism and suggest that previous reports of altered susceptibility to illusions may arise from differences in decision-making, rather than differences in perception per se. Our findings help to elucidate the underlying reasons for atypical responses to perceptual illusions in autism and call for the use of methods that reduce cognitive bias when measuring illusion susceptibility.

Teaching identity matching of braille characters to beginning braille readers.

We taught three children with visual impairments to make tactile discriminations of the braille alphabet within a matching-to-sample format. That is, we presented participants with a braille character as a sample stimulus, and they selected the matching stimulus from a three-comparison array. In order to minimize participant errors, we initially arranged braille characters into training sets in which there was a maximum difference in the number of dots comprising the target and nontarget comparison stimuli. As participants mastered these discriminations, we increased the similarity between target and nontarget comparisons (i.e., an approximation of stimulus fading). All three participants' accuracy systematically increased following the introduction of this identity-matching procedure.

Matching Visual and Acoustic Mirror Forms

This paper presents a comparative analysis of the ability to recognize three mirror forms in visual and acoustic tasks: inversion (reflection on a horizontal axis), retrograde (reflection on a vertical axis) and retrograde inversion (reflection on both horizontal and vertical axes). Dynamic patterns consisting of five tones in succession in the acoustic condition and five square dots in succession in the visual condition were presented to 180 non‐musically expert participants. In a yes/no task, they were asked to ascertain whether a comparison stimulus represented the “target” transformation (i.e., inversion, retrograde or retrograde inversion). Three main results emerged. Firstly, the fact that symmetry pertaining to a vertical axis is the most easily perceived does not only apply to static visual configurations (as found in previous literature) but also applies to dynamic visual configurations and acoustic stimuli where it is in fact even more marked. Secondly, however, differences emerged between the facility with which the three mirror forms were recognized in the acoustic and visual tasks. Thirdly, when the five elements in the stimulus were not of the same duration and therefore a rhythmic structure emerged, performance improved not only in the acoustic but also (even more significantly) in the visual task.

Onset-Duration Matching of Acoustic Stimuli Revisited: Conventional Arithmetic vs. Proposed Geometric Measures of Accuracy and Precision.

Onsets of acoustic stimuli are salient transients and are relevant in humans for the perception of music and speech. Previous studies of onset-duration discrimination and matching focused on whether onsets are perceived categorically. In this study, we address two issues. First, we revisit onset-duration matching and measure, for 79 conditions, how accurately and precisely human listeners can adjust the onset duration of a comparison stimulus to subjectively match that of a standard stimulus. Second, we explore measures for quantifying performance in this and other matching tasks. The conventional measures of accuracy and precision are defined by arithmetic descriptive statistics and the Euclidean distance function on the real numbers. We propose novel measures based on geometric descriptive statistics and the log-ratio distance function, the Euclidean distance function on the positive-real numbers. Only these properly account for the fact that the magnitude of onset durations, like the magnitudes of most physical quantities, can attain only positive real values. The conventional (arithmetic) measures possess a convexity bias that yields errors that grow with the width of the distribution of matches. This convexity bias leads to misrepresentations of the constant error and could even imply the existence of perceptual illusions where none exist. This is not so for the proposed (geometric) measures. We collected up to 68 matches from a given listener for each condition (about 34,000 matches in total) and examined inter-listener variability and the effects of onset duration, plateau duration, sound level, carrier, and restriction of the range of adjustable comparison stimuli on measures of accuracy and precision. Results obtained with the conventional measures generally agree with those reported in the literature. The variance across listeners is highly heterogeneous for the conventional measures but is homogeneous for the proposed measures. Furthermore, the proposed measures show that listeners tend to under- rather than to overestimate the onset duration of the comparison stimuli. They further reveal effects of the stimulus carrier on accuracy and precision which are missed by the conventional measures. Our results have broad implications for psychophysical studies that use arithmetic measures to quantify performance when geometric measures should instead be used.

Relation between Exclusion and Stimulus Equivalence Class Formation in Auditory-Visual and Visual-Visual Matching in Preschoolers

The hypothesis that exclusion performance is a prerequisite for the stimulus equivalence class formation was assessed in preschoolers of about 5 years of age. In Experiment 1, two groups of children were trained in a set of conditional discriminations in a two-choice matching to sample format, Group 1 in an auditory-visual modality baseline, and Group 2 in a visual-visual modality baseline. Exclusion test trials included an undefined (not previously related) comparison stimulus, and a defined (i.e., related in the baseline) comparison stimulus, in the presence of an undefined sample stimulus. Selection of the undefined comparison was recorded as a correct response. Stimulus equivalence class formation was assessed by way of symmetry and transitivity test trials. Experiment 2 replicated the design of the first experiment, with the difference that exclusion was assessed independently and with a different baseline from symmetry and transitivity. Exclusion scores were higher for the auditory-visual groups than the visual-visual groups. In both modalities symmetry scores were superior to those in transitivity. Symmetry showed independent from the exclusion performance, but transitivity was presumably dependent from it in the auditory-visual modality.

Enhancement and suppression of tactile signals during reaching.

The perception of tactile stimuli presented on a moving hand is systematically suppressed. Such suppression has been attributed to the limited capacity of the brain to process task-irrelevant sensory information. Here, we examined whether humans do not only suppress movement-irrelevant but also enhance in parallel movement-relevant tactile signals when performing a goal-directed reaching movement. Participants reached to either a visual (LED) or somatosensory target (thumb or index finger of their unseen static hand) and discriminated 2 simultaneously presented tactile stimuli: a reference stimulus on the little finger of their static hand and a comparison stimulus on the index finger of their moving hand. Thus, during somatosensory reaching the location of the reference stimulus was task-relevant. Tactile suppression, as reflected by the increased points-of-subjective-equality (PSE) and just-noticeable-differences (JND), was stronger during reaching to somatosensory than visual targets. In Experiment 2, we presented the reference stimulus at a task-irrelevant location (sternum) and found similar suppression for somatosensory and visual reaching. This suggests that participants enhanced the sensation of the reference stimulus at the target hand during somatosensory reaching in Experiment 1. This suggestion was confirmed in Experiment 3 using a detection task in which we found lower detection thresholds on the target hand during somatosensory but not during visual reaching. We postulate that humans can flexibly modulate their tactile sensitivity by suppressing movement-irrelevant and enhancing movement-relevant signals in parallel when executing a reaching movement. (PsycINFO Database Record

Effects of stimulus meaningfulness on the acquisition of conditional relations and the emergence of symmetrical relations in adult humans

ABSTRACTThe goal of the present study was to investigate the effects of stimulus meaningfulness of sample and comparison stimuli on the acquisition of conditional relations and the emergence of symmetrical relations. Eight college students were trained on two types of baseline conditional discrimination tasks involving meaningful (English words) and non-meaningful (Swahili words) stimuli. One task involved English samples and Swahili comparisons (English–Swahili), whereas the other task involved Swahili samples and English comparisons (Swahili–English). Test trials, without programmed consequences, presented the symmetry probe of the baseline relations trained. That is, the English–Swahili baseline relations presented on the training trials were presented as the Swahili–English symmetrical relations on the test trials. Similarly, the Swahili–English baseline relations on the training trials were presented as the English–Swahili symmetrical relations on the test trials. The results show that the English–Swahili baseline relations were acquired faster than the Swahili–English baseline relations. The results also show that, relative to the acquisition of the baseline relations, the emergence of symmetrical relations was facilitated and delayed, respectively, on the English–Swahili and Swahili–English test trials. The present results suggest that stimulus meaningfulness of untrained successive discrimination of samples and simultaneous discrimination of comparisons on test trials affects the emergence of symmetrical relations, with the former playing a more important role than the latter.

Psychometric measurement of vocal strain using a matching task with sustained vowel stimuli

Psychometric measurement of voice quality is important for quantitative assessment of dysphonia. Previous work established the efficacy of a single-variable matching task to index vocal breathiness and roughness using appropriately designed comparison stimuli, providing a context-independent perceptual task that improves the validity and accuracy of perceptual data compared to magnitude estimation or rating tasks. Physiologically, vocal strain is characterized by excessive vocal fold adduction during phonation, resulting in a glottal pulse with a low duty cycle. The narrowing of the glottal pulse causes the excitation spectrum roll-off to decrease, resulting in a flattening of the spectrum and significant changes in spectral skewness and kurtosis [Moore et al., 1997]. Analogous to comparison stimuli for breathy and rough measurement, a set of noisy sawtooth waveforms was created using modified step filters that varied in spectral slope 1 dB/octave steps, producing a wide range of perceived strain in the comparison stimuli. The comparison stimuli were used in a listening experiment to measure the perceived strain of a set of 15 samples of /a/ selected from the Kay-PENTAX Disordered Voice Database using stratified sampling. The results validate the strain comparison stimuli and extend the matching task paradigm to the three primary dimensions of voice quality perception.

Prefrontal Neurons Represent Motion Signals from Across the Visual Field But for Memory-Guided Comparisons Depend on Neurons Providing These Signals.

Visual decisions often involve comparisons of sequential stimuli that can appear at any location in the visual field. The lateral prefrontal cortex (LPFC) in nonhuman primates, shown to play an important role in such comparisons, receives information about contralateral stimuli directly from sensory neurons in the same hemisphere, and about ipsilateral stimuli indirectly from neurons in the opposite hemisphere. This asymmetry of sensory inputs into the LPFC poses the question of whether and how its neurons incorporate sensory information arriving from the two hemispheres during memory-guided comparisons of visual motion. We found that, although responses of individual LPFC neurons to contralateral stimuli were stronger and emerged 40 ms earlier, they carried remarkably similar signals about motion direction in the two hemifields, with comparable direction selectivity and similar direction preferences. This similarity was also apparent around the time of the comparison between the current and remembered stimulus because both ipsilateral and contralateral responses showed similar signals reflecting the remembered direction. However, despite availability in the LPFC of motion information from across the visual field, these "comparison effects" required for the comparison stimuli to appear at the same retinal location. This strict dependence on spatial overlap of the comparison stimuli suggests participation of neurons with localized receptive fields in the comparison process. These results suggest that while LPFC incorporates many key aspects of the information arriving from sensory neurons residing in opposite hemispheres, it continues relying on the interactions with these neurons at the time of generating signals leading to successful perceptual decisions. Visual decisions often involve comparisons of sequential visual motion that can appear at any location in the visual field. We show that during such comparisons, the lateral prefrontal cortex (LPFC) contains accurate representation of visual motion from across the visual field, supplied by motion processing neurons. However, at the time of comparison, LPFC neurons can only use this information to compute the differences between the stimuli, if stimuli appear at the same retinal location, implicating neurons with localized receptive fields in the comparison process. These findings show that sensory comparisons rely on the interactions between LPFC and sensory neurons that not only supply sensory signals but also actively participate in the comparison of these signals at the time of the decision.

Robot-assisted assessment of wrist proprioception: does wrist proprioceptive acuity follow Weber's law?

Proprioception is essential for planning and controlling limb posture and movement. In our recent work, we introduced a standardized robot-aided method for measuring proprioceptive discrimination thresholds at the wrist to obtain reliable and accurate measures of proprioceptive acuity. Weber's law defines discrimination thresholds as a constant ratio between the just noticeable difference and the reference or standard stimulus. Reporting Weber's fractions thus provides the possibility of comparing results with the reports of others collected worldwide. This work aims to determine that Weber's Law holds for proprioceptive discrimination thresholds and to provide Weber's fraction for wrist joint proprioception. To this end, eight healthy subjects experienced two passive wrist movements of different amplitude and verbally indicated which was larger. An adaptive psychophysical procedure established the amplitude of the largest stimulus according to participants' responses. This comparison stimulus was then compared to a standard stimulus amplitude of 10°, 20°, 30° or 40°. The discrimination thresholds for each standard stimulus were established at the 75% correct response level. The obtained thresholds followed Weber's Law indicating that larger amplitudes were associated with higher discrimination thresholds. Based on a linear regression function the overall Weber's fraction, defined as the slope of the line, was computed to be 0.09. This result expands the present limited knowledge on wrist proprioception showing that its proprioceptive acuity follows Weber's law.

Effects of Between-classes Negative Relations Training on Equivalence Class Formation across Training Structures

This study compared three three-choice matching to sample (MTS) procedures on their probability to form equivalence relations for each of the three training structures: one to many (OTM), many to one (MTO), and linear series (LS). All three MTS procedures established the same within-class positive relations, but they differed in the number of between-class negative relations included in their baseline trials, with two in the standard (STD) matching procedure, one in the semi-standard (SEMI) procedure, and none in the altered (ALT) procedure. Positive and negative control baseline relations were assessed by using trials including novel stimuli or a blank comparison stimulus before symmetry and equivalence performance testing. The matching procedures did not differ in the rate of positive control that they yielded, but they did in the rate of negative control. The number of between-class negative relations in the baseline trials was directly related to the probability of equivalence class formation. However, this relation was different across training structures: it was lineal for the OTM structure, did not differ between the STD and SEMI procedures for the MTO structure, and did not differ between the SEMI and ALT procedures for the LS structure. Testing of positive baseline control by means of a blank comparison stimulus as an incorrect choice and testing of the negative baseline control by using novel stimuli as the correct choice proved more sensitive to the matching procedures and most discriminative between participants who formed equivalence relations and those who did not.

Computational Simulation of Equivalence Class Formation Using the go/no-go Procedure with Compound Stimuli.

Research about equivalence has commonly utilized human participants as experimental subjects. More recently, computational models have been capable of reproducing performances observed in experiments with humans. The computational model often utilized is called RELNET, and it simulates training and testing trials of conditional relations using the matching-to-sample procedure (MTS). The differentiation between sample stimulus and comparison stimuli, indispensable in MTS, implies operational difficulties for simulations. For this reason, new studies seek to utilize alternative procedures to MTS, which do not differentiate the functions of the antecedent stimuli. This work evaluated the possibility of developing a new computational model to simulate equivalence class formation using the go/no-go procedure with compound stimuli. In Experiment 1, artificial neural networks were utilized to simulate training of the AB and BC relations as well as the testing of the AC relation. The results showed that four out of six runs demonstrated equivalence class formation. Experiment 2 evaluated whether the additional class training performed in Experiment 1, which was analogous to the simulation of pre-experimental experience of human participants, would be essential for simulating the establishment of equivalence classes. It was found that it was not possible to simulate equivalence class formation without the additional class training. Altogether, the experiments show that it is possible to simulate equivalence class formation using the go/no-go procedure with compound stimuli and that it is necessary to conduct additional class training. The model developed is, therefore, an alternative to RELNET for the study of equivalence relations using computational simulations.

Short-term memory effects on visual global/local processing in tufted capuchin monkeys (Sapajus spp.).

Nonhuman primates, differently from humans, are less proficient at processing global properties of visual compound stimuli. It has been suggested that humans preferentially process stimuli globally because this enables a more economical encoding of the stimuli. In this study we assessed the role of short-term memory (STM) in global/local processing by presenting tufted capuchin monkeys with Navon-type hierarchical figures in both simultaneous and delayed matching-to-sample tasks. Capuchins' ability to discriminate hierarchical stimuli was evaluated as a function of increasing delay intervals (0.0, 0.5, 1.0, 2.0 and 3.0 sec) between the disappearance of the sample and the presentation of the comparison stimuli. The results showed that recognition accuracy for local features was above chance level with delays of up to 3.0 sec, as previously reported when capuchins were faced with nonhierarchical stimuli. By contrast, the recognition of global configurations was above chance level in simultaneous, 0.0 and 0.5 sec delay conditions but not at delay intervals of 1.0 sec or longer. These findings indicate that capuchins' propensity to process the local properties of visual stimuli can be observed when a delay is interposed between the presentation of sample and comparison stimuli and was not reversed by increasing the delay. Moreover, our results show that capuchins' local propensity was not reversed by increasing stimulus size. Overall, our study confirms crucial differences between human and nonhuman primates and adds new insights into the comparative research on visual grouping functions of these species. (PsycINFO Database Record

Patterns of eye movement in matching-to-sample tasks

The present study evaluated whether during a matching-to-sample procedure (MTS), the time spent observing stimuli is related to the establishment of selection or rejection controlling relationships in human participants. It also evaluated whether different response topographies (i.e., participants using the keyboard or mouse) would influence the duration of eye fixations. Ten college students participated. The procedure established conditional relationships among six sets of abstract stimuli. Five participants selected the comparison stimuli using a computer mouse and five used a keyboard. An eye-scan device recorded eye movements throughout the training procedure. After participants completed training, probes verified whether the conditional relationships learned were controlled by selection (e.g., if A1, select B1), by rejection (e.g., if A1, reject B2), or both. All participants displayed a similar pattern of stimuli observation. Time spent observing the sample stimulus (e.g., A1) was longer than observing the comparison stimuli (e.g., B1 and B2). Time spent observing S+ (positive stimuli; e.g., B1) was longer than observing S- (negative stimuli; e.g., B2). Duration of eye fixation was not related to selection or rejection controlling relationships, but different response topographies appeared to modulate the amount of time spent observing stimuli.

DISCRIMINAÇÕES CONDICIONAIS ENTRE ESTÍMULOS VISUAIS E TESTES DE SIMETRIA EM MELIPONAS

Oito melíponas (Melipona quadrifasciata) foram expostas a uma versão adaptada do procedimento de emparelhamento arbitrário com o modelo (matching-to-sample) em que a presença ou ausência de luz era empregada como estímulo condicional e as cores azul e amarelo como estímulos discriminativos. As cores eram apresentadas por semicírculos de material emborrachado sustentados por duas caixas retangulares de madeira, cada uma posicionada sobre uma caixa experimental a uma distância de 15 cm uma da outra. Cada lâmpada estava localizada sobreumadascaixas. As caixas experimentais eram de material acrílico com um painel superior de alumínio. Cada caixa era equipada com um alimentador operado externamente por uma haste e possuía um conjunto de pequenos orifícios no painel de alumínio que davam acesso ao xarope. Uma abelha podia voar da colméia para o aparato experimental e obter o xarope condicionalmente ao pouso direto sobre o estímulo de comparação definido como S+ em uma tentativa particular. Depois de instalada a linha de base, foram conduzidas sondas de simetria em extinção, intercaladas com tentativas de linha de base. Nas sondas, os discos coloridos tinham a função de estímulos condicionais (as duas caixas mostravam os discos de uma mesma cor, azul ou amarelo) e a presença e a ausência de luz eram usadas como estímulos discriminativos. As discriminações condicionais foram estabelecidas com todas as abelhas e seis entre as oito abelhas alcançaram o critério de simetria emergente (ao menos cinco tentativas entre seis). Estesresultadosestendemachadospréviossobrediscriminaçõescondicionaiseemparelhamento de identidade em abelhas. Contudo, no presente procedimento os estímulos tinham posição fixa, o que permite questionar se os comportamentos observados revelam propriedades simétricas (emergentes) ou apenas o controle por componentes de estímulos compostos (diretamente aprendidos). Palavras-chave: discriminação condicional, simetria, abelhas (Melipona quadrifasciata).

Eye Movements During Conditional Discrimination Training

We examined eye movements in younger and older adults during conditional discrimination training and testing for responding in accordance with stimulus equivalence. During training, we measured fixation duration and fixation rate for both the sample and comparison stimuli. During testing, we measured fixation duration and fixation rate for the comparison stimuli only. In addition, we measured the establishment of conditional discriminations and likelihood of responding in accordance with stimulus equivalence. The results showed that the effect of the differential reinforcement procedure occurred more slowly in the older participants. Fixation rate and fixation duration toward the sample stimulus was similar for both groups, whereas fixation rate and fixation duration toward the comparison stimuli were generally higher for the older adults, particularly for those who failed to respond in accordance with stimulus equivalence. Fixation rate and fixation duration generally decreased across training, with a stepwise increase in both behaviors during testing of the baseline conditional discriminations, symmetry, and equivalence relations. The same pattern recurred in the last part of testing, although generally with shorter fixation durations and lower fixation rates relative to the beginning of testing.

Effects of Presentation Type and Visual Control in Numerosity Discrimination: Implications for Number Processing?

Performance in a non-symbolic comparison task in which participants are asked to indicate the larger numerosity of two dot arrays, is assumed to be supported by the Approximate Number System (ANS). This system allows participants to judge numerosity independently from other visual cues. Supporting this idea, previous studies indicated that numerosity can be processed when visual cues are controlled for. Consequently, distinct types of visual cue control are assumed to be interchangeable. However, a previous study showed that the type of visual cue control affected performance using a simultaneous presentation of the stimuli in numerosity comparison. In the current study, we explored whether the influence of the type of visual cue control on performance disappeared when sequentially presenting each stimulus in numerosity comparison. While the influence of the applied type of visual cue control was significantly more evident in the simultaneous condition, sequentially presenting the stimuli did not completely exclude the influence of distinct types of visual cue control. Altogether, these results indicate that the implicit assumption that it is possible to compare performances across studies with a differential visual cue control is unwarranted and that the influence of the type of visual cue control partly depends on the presentation format of the stimuli.

Context controls access to working and reference memory in the pigeon (Columba livia).

The interaction between working and reference memory systems was examined under conditions in which salient contextual cues were presented during memory retrieval. Ambient colored lights (red or green) bathed the operant chamber during the presentation of comparison stimuli in delayed matching-to-sample training (working memory) and during the presentation of the comparison stimuli as S+ and S- cues in discrimination training (reference memory). Strong competition between memory systems appeared when the same contextual cue appeared during working and reference memory training. When different contextual cues were used, however, working memory was completely protected from reference memory interference.

Influence of Cigarette Package Brand on the Emotional Impact of Tobacco-Warning Images That Cover 30% of Cigarette Packs in Smokers and Nonsmokers

Research on the emotional impact of tobacco-warning images (TWIs) has not evaluated the role of context (ie, cigarette packs) as a modulator of the emotional response to TWIs. The objective of the present study was to identify the influence of the cigarette package brand on the emotional impact of TWIs that cover 30% of cigarette packs in smokers and nonsmokers using a specific methodology for the study of emotion. The participants included 95 smokers and 111 nonsmokers who observed three TWIs under two conditions: TWIs that covered 30% of cigarette packs and TWIs alone, without brands. Additionally, 18 pictures from the International Affective Picture System were presented as comparison stimuli and to reduce the effect of habituation. The Self-Assessment Manikin was used to assess valence, arousal, and dominance dimensions. TWIs that covered 30% of cigarette packs were evaluated as least aversive, with lower ratings of arousal and higher ratings of dominance in both groups. Differences in the valence, arousal, and dominance dimensions were found between groups. Smokers rated TWIs that covered 30% of cigarette packs as less aversive and more arousing and gave them lower dominance scores compared with nonsmokers. The results suggest that cigarette packages modulate the emotional impact of TWIs, especially in smokers, and the minimum size of TWIs (ie, 30% of the front and back of the package) is not sufficiently large to generate an emotional impact associated with avoidance behavior. Cigarette packages modulate the emotional impact of TWIs, especially in smokers. The cigarette package itself is an appetitive context that captures the attention of the observer and decreases the aversive emotional response to the TWIs. The minimum size of TWIs (ie, 30% of the front and back of the package) is not sufficiently large to generate an emotional impact associated with avoidance behavior.