The Role of Gesture Types and Spatial Feedback in Haptic Communication.

The sense of touch is a fundamental part of social interaction as even a short touch from another person can elicit emotional experiences. Previous studies on haptic communication indicate that the benefits of interpersonal touch exist even when touch is artificially mediated between people that are physically apart. In the current study an evaluation of three input gestures (i.e., moving, squeezing, and stroking) was conducted to identify preferred methods for creating haptic messages using a hand-held device. Furthermore, two output methods (i.e., one or four haptic actuators) were investigated in order to determine whether representing spatial properties of input gestures haptically provides additional benefit for communication. Participants created haptic messages in four example communication scenarios. The results of subjective ratings, postexperimental interviews, and observations showed that squeezing and stroking were the preferred ways to interact with the device. Squeezing was an unobtrusive and quick way to create haptic content. Stroking, on the other hand, enabled crafting of more detailed haptic messages. Spatial haptic output was appreciated especially when using the stroking method. These findings can help in designing haptic communication methods for hand-held devices.

Methods for Presenting Braille Characters on a Mobile Device with a Touchscreen and Tactile Feedback.

Three novel interaction methods were designed for reading six-dot Braille characters from the touchscreen of a mobile device. A prototype device with a piezoelectric actuator embedded under the touchscreen was used to create tactile feedback. The three interaction methods, scan, sweep, and rhythm, enabled users to read Braille characters one at a time either by exploring the characters dot by dot or by sensing a rhythmic pattern presented on the screen. The methods were tested with five blind Braille readers as a proof of concept. The results of the first experiment showed that all three methods can be used to convey information as the participants could accurately (91-97 percent) recognize individual characters. In the second experiment the presentation rate of the most efficient and preferred method, the rhythm, was varied. A mean recognition accuracy of 70 percent was found when the speed of presenting a single character was nearly doubled from the first experiment. The results showed that temporal tactile feedback and Braille coding can be used to transmit single-character information while further studies are still needed to evaluate the presentation of serial information, i.e., multiple Braille characters.

Neural network and wavelet recognition of facial electromyographic signals.

The present aim was to explore the possibilities of using neural networks for recognizing significant changes in electrical activity of human facial muscles. We used multilayer perceptron neural networks to recognize bursts of electromyographic signals recorded with bipolar surface electrodes from two subject's facial muscles. Wavelets were applied for the detection of high frequency components of electromyographic signals. Coefficients of wavelets were used as an input to a neural network in order to differentiate bursts from the signals. The results showed that the recognition of bursts was very successful resulting to 84-97 percent total accuracies. The results were very encouraging and suggest further that the measurement of facial muscle activity may be a potentially useful computer input signal, for example, for affective computing which can be seen as a future versatile interaction between the computer and the user.

Modulation of neutral face evaluation by laterally presented emotional expressions.

The present study examined hemispheric asymmetries in emotional processing. 40 right-handed women were presented sequences of Happy, Sad, and Disgusted facial expressions to their left and right visual fields followed by a Neutral face presented to ipsi- or contralateral visual field. After Happy sequences, Neutral faces were rated as significantly more pleasant than after Sad sequences. In respect to hemispheric asymmetries, the analyses gave a significant effect of visual field only for Sad sequences. The ratings of Neutral faces were significantly more positive after presentations of Sad sequences to the left than to the right visual field. These modulational effects are suggested to support recent findings of hemispheric asymmetries of human emotions.

Modulation of human auditory information processing by emotional visual stimuli.

Auditory event-related potentials mismatch negativity (MMN) and N100 were recorded from seven subjects while they read text and watched emotionally negative, neutral, and positive pictures varying in valence and arousal. The MMN reflects automatic detection of change in auditory stimulus stream. Functionally different N100 is triggered by onset of various auditory stimuli. The N100 was stabile during all visual conditions. The MMN was very similar during text reading, and neutral and negative slide viewing, but was significantly attenuated during viewing of positively valenced slides. We suggest that visual emotional information of high positive valence and low arousal is a signal of nonthreatening and nonappetitive environment. This kind of environment probably reduces the need for auditory change detection.

Facial electromyographic responses to vocal affect expressions.

In this study we investigated facial electromyographic (EMG) responses to vocal affect expressions. We also measured emotion-related action tendencies by requesting the subjects to indicate their tendency to approach or withdraw from the person uttering the stimulus word. In addition, emotional contagion (EC) was measured with a questionnaire-based scale. The results showed that hearing the expression of anger increased EMG activity in the subjects' brow region more than hearing contentment. In contrast, the expression of contentment activated the periocular muscle region more than anger. The expressions of anger elicited behavioral withdrawal responses, whereas the neutral expressions and contentment evoked approach responses. Subjects scoring low and high on EC exhibited different patterns of EMG responses. The results support the view that negative and positive affects are contagious from hearing human vocal affect expressions.

Facial and emotional reactions to Duchenne and non-Duchenne smiles.

The purpose of the study was to investigate facial and emotional reactions while viewing two different types of smiles and the relation of emotional empathy to these reactions. Facial EMG was recorded from the orbicularis oculi and zygomaticus major muscle regions while subjects individually watched two blocks of stimuli. One block included posed facial expressions of the Duchenne smile (a felt smile) and a neutral face, the other block included expressions of another type of smile called non-Duchenne smile (an unfelt smile) and a neutral face. Emotional experiences were asked after each stimulus block. Finally, a measure of empathy was given. Facial EMG reactions differentiated between the neutral face and the Duchenne smile but not between the neutral face and the non-Duchenne smile. The Duchenne smile block induced experience of pleasure for the subjects who saw it as the first stimulus block. Empathy was correlated to the rated experiences of pleasure and interest after the Duchenne smile block.