Frequent eye blinking when talking can sometimes be associated with lying, but it's not a definitive indicator. Here are some points to consider:

- **Stress and Anxiety:** Increased blinking can be a sign of stress or anxiety, which might occur when someone is lying due to the fear of being caught. However, these emotions can also arise from other non-deceptive situations like nervousness in social settings, public speaking, or when someone is under scrutiny for any reason.

- **Physiological Responses:** Blinking can increase due to various physiological reasons unrelated to deceit, such as dry eyes, bright lighting, or even fatigue. Some people naturally blink more than others.

- **Context and Baseline Behavior:** To interpret blinking as a possible sign of lying, one would need to know the individual's baseline behavior. If they normally blink a lot, then an increase might not be significant. Conversely, if they typically blink less, an increase could be more telling.

- **Other Nonverbal Cues:** Relying solely on blinking to detect lies is risky. Lying typically involves a combination of behaviors, including changes in voice pitch, micro-expressions, body posture, and other non-verbal cues. 

- **Cultural and Individual Differences:** Cultural norms around eye contact and non-verbal communication can affect how much someone blinks. Additionally, some individuals might have trained themselves or naturally have less control over their blink rate when under pressure.

- **Deception Research:** While there's research on nonverbal cues of deception, results are often mixed or context-dependent. No single behavior definitively indicates lying, and experts like Paul Ekman, who study micro-expressions and body language, caution against oversimplifying these signals.

In conclusion, while frequent eye blinking might be part of a cluster of behaviors suggesting deception, it should not be used in isolation to determine if someone is lying. It's crucial to consider the broader context, the person's usual behavior, and other signs before jumping to conclusions. If you're concerned about someone's honesty, it's often better to look for more consistent and corroborative signs of deceit or, where appropriate, to communicate directly about your concerns.