Questions for Development of Lower Order Cognitive Processes in Infancy I and II

Answer the following questions in your own words.

1. The y-axis in the graph below denotes frequency, with low, or deep, sounds associated with low frequencies (e.g. 250 Hz) and high sounds associated with high frequencies (e.g. 8,000 Hz). The x-axis denotes the sound level (or threshold) at which hearers detect sound in a particular frequency range. Thus, a lower line means better detection of a sound.

Given this information,

1) what similarity do you observe in infant and adult hearing between 500 and 4,000 Hz?

2) What sounds are most difficult for infants of all ages in the graph, high or low sounds? Explain each of your answers.

2. The figure below shows infants' looking preferences for different visual stimuli (e.g., a concentric vs. a horizontal pattern, a checkerboard vs. a solid pattern, a cross vs. a circle, two triangles).

1) Identify two stimulus pairs from the figure that demonstrate that infants discriminate between different visual stimuli. Justify your answer.

2) What general conclusion can you draw about infant preferences from their looking times to all of the stimuli below? Justify your answer.

Hint: the audio lecture explains the logic supporting the data from the experiment in the figure.

3. Early work with newborn infants suggested they had a preference for upright faces. Cassia et al. (2004) asked whether these preferences reflect expectations about the specific locations of features on faces such as the eyes, eyebrows, nose and mouth or a less specific preference that faces have most of their features on top.

1) Describe the looking time results depicted in the graphs for Experiments 2 and 3 in terms of whether total fixation (e.g. looking time) reflects a statistically-supported preference.

Note: a p value less than .05 denotes a statistical difference in looking time between the two stimulus types for that experiment.

2) Describe how the two experiments together support the conclusion that infants do not have expectations about the specific locations of features on faces.

4. Explain in your own words how an infant's ability to imitate an adult who is sticking out his tongue is an example of cross-modal perception.

5. The results in the graph below (discussed in the audio lecture) show infant looking to a stimulus and changes in infants' heartrate during this period. 1) Describe how the experimenters measure orienting (OR), sustained attention (SA), and termination of attention (AT). 2) Why is it important to supplement infant looking with measures heart rate?

6. In the study on recognition memory using the objects below, why did experimenters familiarize half of the infants with the cow (as in the display below) and half with the buggy? Hint: This question has to do with the ability to draw conclusions that generalize across all participants in a scientific study. Think about the fact that different infants may have preferences for one type of object over another. How would using two different stimuli for familiarization counteract infants' preferences?